Question: What was the nickname for the other steel helmet used with the Mk III in WWII?

Context paragraphs:
Mk 6 helmet: The Mk 6 helmet was the standard combat helmet of the British Armed Forces.  The Mk 6 replaced the Mk IV helmet (more correctly titled - Helmet Steel MK IV, General Service).  The jump in MK numbers is thought due to the confusion surrounding the MK IV helmet utilising the MK V lining, introduced in 1959.  The MK 6, introduced into service from 1985, is designed to accept modern ear protection, Bowman personal radios, and respirators.  The helmet is manufactured by NP Aerospace, and is reported to have an "almost unlimited service life" by the manufacturer.

Ford GT40: The Ford GT40 is a high-performance endurance racing car based on the British Lola Mk6, with the Mk I, Mk II, and Mk III designed and built in England and the Mk IV built in the United States.  The range was powered by a series of American-built engines modified for racing.  The GT40 won the 24 Hours of Le Mans four consecutive times, from 1966 to 1969 (1966 being the Mk II, 1967 the Mk IV, and 1968-1969 the oldest chassis design, the Mk I), including a 1-2-3 finish in 1966.  In 1966, with Henry Ford II himself in attendance at Le Mans, the Mk II GT40 provided Ford with the first overall Le Mans victory for an American manufacturer, and the first victory for an American manufacturer at a major European race since Jimmy Murphy´s triumph with Duesenberg at the 1921 French Grand Prix.  The Mk IV GT40 that won Le Mans in 1967 is the only car designed and built entirely in the United States to achieve the overall win at Le Mans.

SSh-68: The SSh-68, Russian: СШ-68 (стальной шлем образца 1968 года/stalnoy shlyem, or steel helmet) (English: SSh-68 steel helmet model 1968) - is a steel helmet of the Soviet and then Russian Armed Forces.  The SSh-68 is further development of combined-arms helmet SSh-60.  It differs primarily in its greater strength, greater front slope of the dome and the shorter outer edge.  It is usually painted in dark green.

Cruiser Mk IV: The Cruiser tank Mk IV (A13 Mk II) was a British cruiser tank of the Second World War.  It followed directly on from the Tank, Cruiser, Mk III (A13 Mk I).  The first Mk IVs were Mk IIIs with extra armour fitted to the turret.  Later Mk IVAs were built with the complete extra armour.  The tank was used in France in 1940 and in the early part of the war in North Africa, before being withdrawn from service.

Riley &amp; Scott Mk III: The Riley & Scott Mark III (Mk III) was a sports prototype auto racing car developed by Bob Riley, Bill Riley, and Mark Scott of Riley & Scott Cars Inc..  Initially designed in 1993, the car was created for the World Sports Car (WSC) category which was to debut in the North American IMSA GT Championship during their 1994 season.  It was not until 1995 that the first Mk III was completed, but the construction of further cars allowed a variety of teams to campaign in several North American and European racing series, including competing at the 24 Hours of Le Mans.

Modèle 1978 helmet: The Modèle 1978 helmet is a modern military steel helmet used by the French Army under the "F1" designation and commonly called "heavy helmet" (other nicknames include "locomotive skin cap").  It replaced the Modèle 1951 helmet, and is superseded by the SPECTRA helmet.

Hawley Products Company: Hawley Products Company is a manufacturer of loudspeaker components.  The company is the oldest manufacturer of loudspeaker diaphragms in the world.  Historically, the company produced a variety of products composed of fibrous or plastic materials, including helmets, globes, microwave trays, automotive components, suitcases, and furniture.  Most notably, the company is remembered for its World War II military helmets and helmet liners used by soldiers in the United States Army, Marines, and Navy.  Hawley Products is the original designer of the M1 steel helmet liner.  The company is also one of the two original manufacturers of the M1 steel helmet liner, alongside General Fibre Company.  Additionally, Hawley Products designed and manufactured several versions of the pressed fiber military sun helmet used by the US military during World War II.  The military continued to use this sun helmet throughout most of the 20th century, including Naval personnel during the Persian Gulf War.

Mk III helmet: The Mk III Helmet was a steel military combat helmet first developed for the British Army in 1941 by the Medical Research Council.  First worn in combat by British and Canadian troops on D-Day, the Mk III and Mk IV were used alongside the Brodie helmet for the remainder of the Second World War.  It is sometimes referred to as the "turtle" helmet by collectors, because of its vague resemblance to a turtle shell, as well as the 1944 pattern helmet.

Stahlhelm: Stahlhelm (plural "Stahlhelme") is German for "steel helmet".  The Imperial German Army began to replace the traditional boiled leather Pickelhaube (spiked combat helmet) with the Stahlhelm during World War I in 1916.  The term "Stahlhelm" refers both to a generic steel helmet, and more specifically to the distinctive (and iconic) German design.

Brodie helmet: The Brodie helmet is a steel combat helmet designed and patented in London in 1915 by John Leopold Brodie.  In modified form it became the Helmet, steel, Mark I in Britain and the M1917 Helmet in the U.S. Colloquially, it was called the shrapnel helmet, Tommy helmet, tin hat, and in the United States the doughboy helmet.  Worn by Australians during WW2 and sometimes known as Panic Hat.  It was also known as the dishpan hat, tin pan hat, washbasin, battle bowler (when worn by officers), and Kelly helmet.  The US version, the M1917, was copied from the British Mk 1 steel helmet of 1916.  The German Army called it the "Salatschüssel" (salad bowl).  The term "Brodie" is often mis-used.  It is correctly applied only to the original 1915 "Brodie's Steel Helmet, War Office Pattern".

Supporting paragraphs: Mk III helmet Brodie helmet
Answer: Panic Hat