Question: Martin Elbourne had her first job here, what grade was the House listed as?

Context paragraphs:
Albert S. Sholes House: The Albert S. Sholes House, located in Cornelius, Oregon, is a house listed on the National Register of Historic Places (NRHP).  Built in 1909, the bungalow was designed by Richard Martin Jr. for banker Albert Sholes.

Martin Elbourne: Martin Elbourne (born 19 January 1957 in Carlisle, Cumbria) is an English performing arts promoter.  Elbourne was brought up near the village of Knebworth, Hertfordshire.  His first job, at age fifteen, was working for the local stately home Knebworth House which in the mid-seventies became the biggest venue in the United Kingdom for outdoor shows and hosted bands such as Led Zeppelin, The Rolling Stones and Pink Floyd.

Herman C. Timm House: The Herman C. Timm House is a house listed on the National Register of Historic Places in New Holstein, Wisconsin, United States.  The house is a significant example of Stick style architecture, a rather rare predecessor of Queen Anne Style architecture.  The house was the home of an original settler and prominent citizen, Herman C. Timm.

Marshlands Plantation House: Marshlands Plantation House, in Charleston, South Carolina, is an historic plantation house listed in the National Register of Historic Places on March 30, 1973.  A 2 ⁄ -story Federal-style plantation home, it was built in 1810.  The house was relocated in the 1960s from its original location on the site of the United States Navy Shipyard.  The Navy had announced it would have to demolish the empty house if it could not be relocated with $15,000 it had set aside for the purpose.  The City of Charleston took temporary possession of the house, transferring it to the College of Charleston which relocated it for preservation to James Island.

Internet censorship in Morocco: Internet censorship in Morocco was listed as selective in the social, conflict/security, and Internet tools areas and as no evidence in the political area by the OpenNet Initiative (ONI) in August 2009.  Freedom House listed Morocco's "Internet Freedom Status" as "Partly Free" in its 2013 "Freedom on the Net" report.

A. V. Peters House: The A. V. Peters House aka the Peters-Liston-Wintermeier House, located in Eugene, Oregon, United States, is a house listed on the National Register of Historic Places.  The house was built circa 1870 for merchant Andrew Vincent Peters and his wife Mary Elizabeth "Lizzy" (Shaw) Peters on the southeast corner of 10th and Pearl streets (661 Pearl Street was the original address), and moved to its current location in 1912.  A 1-1/2 story 1890s carriage house was also moved onto the property at about the same time.  Considered one of Oregon's finest examples of the Rural Gothic Style, the house was built using a design from a pattern book by Henry W. Cleaveland published in 1856.  Another pattern book, "Woodward's National Architect", published in 1869, was also used as a reference for some of the decorative elements of the house.  The house features board and batten siding, scrollwork balcony detailing, and bracketed eaves supporting the steeply pitched roof.

Knebworth House: Knebworth House is a country house in the civil parish of Knebworth in Hertfordshire, England.  It is a Grade II* listed building.

Ercildoun, Pennsylvania: Ercildoun, population about 100, is an unincorporated community in East Fallowfield Township, Chester County, Pennsylvania, United States.  The hamlet was founded by Quakers and was an early center of the abolitionist movement.  In 1985 the entire hamlet, including 31 properties, was listed as a historic district on the National Register of Historic Places.  Of these properties two were vacant land, 14 were significant buildings, ten were contributing buildings, and five buildings, built in the 1950s, were non-contributing.  The Lukens Pierce House, an octagon house listed separately on the U.S. National Register of Historic Places, is located about half a mile northwest of the hamlet.  Ercildoun is one of about ten hamlets in the township, which has no cities or towns, but has 31 sites listed on the National Register.  It is one of the larger hamlets, located near the center of the township, and historically among the best known.  The city of Coatesville is about 3 miles north.

Grade I listed war memorials in England: There are 20 Grade I listed war memorials in England, out of over 3,000 listed war memorials.  In the United Kingdom, a listed building is a building or structure of special historical or architectural importance; listing offers the building legal protection against demolition or modification, which requires permission from the local planning authority.  Listed buildings are divided into three categories—grade I, grade II*, and grade II—which reflect the relative significance of the structure and may be a factor in planning decisions.  Grade II accounts for 92% of listed buildings, while grade II* is an intermediate grade accounting for 5.5%; grade I holds the remaining 2.5% of listed buildings and is reserved for structures of exceptional significance.  Grade I listed war memorials are deliberately very few, though several have been upgraded to grade I status as part of commemorations around the First World War centenary.  A war memorial listed at grade I will be of exceptional interest for its design and artistic merit and will be of great historical interest.  Such memorials are often the work of famous architects or sculptors, amongst the most prolific of whom was Sir Edwin Lutyens, whose memorials account for a third of all those listed at grade I. Lutyens designed dozens of war memorials across the United Kingdom and elsewhere in the Commonwealth, including the Cenotaph on Whitehall in London—the focus for the national Remembrance Sunday services—and the Arch of Remembrance in Leicester—the largest of Lutyens' war memorials in Britain; both are listed at grade I.  As part of the commemorations of the centenary of the First World War, Historic England—the government body responsible for listing in England—is running a project with the aim of significantly increasing the number of war memorials on the National Heritage List for England.

Grade II* listed war memorials in England: There are 61 Grade II* listed war memorials in England, out of over 2,000 listed war memorials.  In the United Kingdom, a listed building is a building or structure of special historical or architectural importance; listing offers the building legal protection against demolition or modification, which requires permission from the local planning authority.  Listed buildings are divided into three categories—grade I, grade II*, and grade II—which reflect the relative significance of the structure and may be a factor in planning decisions.  Grade I is the most significant and accounts for 2.5% of listed buildings, while grade II accounts for 92%.  Grade II* is the intermediate grade accounting for the remaining 5.5%; it is reserved for "particularly important buildings of more than special interest".  A war memorial listed at grade II* may be of particular artistic interest or accomplishment, of a highly unusual design, or of significant historical interest below that required for grade I.  It is explicitly unnecessary for the architect or sculptor to be well known in order for a memorial to be listed at grade II*.  As part of the commemorations of the centenary of the First World War, Historic England—the government body responsible for listing in England—is running a project with the aim of significantly increasing the number of war memorials on the National Heritage List for England.

Supporting paragraphs: Martin Elbourne Knebworth House
Answer: Grade II