Question: In which American reality television series airing on the History channel  Koker and his staff follows as they restore and modify classic automobiles and motorcycles?

Context paragraphs:
Desert Car Kings: Desert Car Kings is a reality television series that debuted on the Discovery Channel on January 26, 2011.  It is based on the McClure family, who run Desert Valley Auto Parts in Phoenix, Arizona.  The show's main characters, Jason and his father Ron, restore classic cars on a limited time-frame; restorations are usually given until their next auction.  The operation houses more than 10,000 rust-free vehicles on more than 100 acres of dry Arizona land.  Restorations have included a 1965 Ford Thunderbird, a 1970 Oldsmobile 442, a 1962 Ford Galaxie, a 1964 Plymouth Barracuda, a 1955 Ford F-100, and a 1966 Chevrolet Chevelle SS.  With average ratings, critics vary in their opinion on the show.  Some praise it, others calling it superficial.  With its time slot competing with cable television's highest-rated reality show at the time (A&E's, Storage Wars), the show had several factors working against it.  Despite the final episode airing over a year earlier, according to a May 6, 2012 Discovery Channel Facebook posting, the show had not been canceled.  Finally, an announcement came from Discovery Channel that a second season of Desert Valley Car Kings was not picked up due to production costs.  Since its cancellation, it has begun airing reruns on the Velocity cable television network.  As of July 2015 it is also airing in the UK on the Quest station (Recorded in 2011 - Some confusion, UK viewers think it is more recent).

American Restoration: American Restoration is an American reality television series airing on the History channel.  Produced by Leftfield Pictures, the first six seasons were recorded in Las Vegas, Nevada, where it chronicled the daily activities at "Rick's Restorations", an antique restoration shop, with its owner Rick Dale, his staff, and teenage son, as they restore various vintage items to their original condition.

List of American Restoration episodes: "American Restoration" is an American reality television series airing on the History channel.  Produced by Leftfield Pictures, the series is filmed in Las Vegas, Nevada, where it chronicles the daily activities at "Rick's Restorations", an antique restoration store, with its owner Rick Dale, his staff, and teenage son, as they restore various vintage items to their original condition.

Vanderpump Rules: Vanderpump Rules is an American reality television series airing on Bravo that debuted on January 7, 2013, with the first season originally eight episodes.  A spin-off of "The Real Housewives of Beverly Hills", the series features "The Real Housewives of Beverly Hills" cast member Lisa Vanderpump in the title role and her staff at Vanderpump's West Hollywood, California, restaurant SUR.

American Eats: American Eats is an American reality television show that aired on The History Channel from June to November 2006.  The program follows in the footsteps of the earlier reality television shows "American Eats: History on a Bun" and "American Eats: More American Eats", both of which also aired on the History Channel.  The series was produced by Atlas Media Corp.

Hairy Bikers (U.S. TV series): Hairy Bikers is an American reality television series which aired on History Channel.  The show was based on the British show of the same name and featured chef Paul Patranella, and his friend Bill Allen, following the original's format as the two traverse the United States on motorcycles.  Patranella was a former chef for The White House, acting for a time as George W. Bush's personal chef.  Allen owns a motorcycle repair shop in Texas.

Counting Cars: Counting Cars is an American reality television series, shown on History, and produced by Leftfield Pictures.  The series, which is the third spinoff of "Pawn Stars", is filmed in Las Vegas, Nevada, where it chronicles the daily activities at Count's Kustoms, an automobile restoration and customization company owned and operated by Danny Koker, who previously appeared as a recurring expert on "Pawn Stars".  In a format similar to another "Pawn Stars" spinoff, "American Restoration", the series follows Koker and his staff as they restore and modify classic automobiles and motorcycles.  "Counting Cars" debuted on August 13, 2012.

American Digger (TV series): American Digger is an American reality television series airing on Discovery Networks.  The show follows former professional wrestler Frank Huguelet (aka Ric Savage) and his company American Savage as they search the United States for buried historical artifacts.  The second season of the show was retitled Savage Family Diggers as Savage's wife Rita and son Nick join the crew.

Bad Sex: Bad Sex is an American reality television series airing on Logo.  The series follows 10 diverse participants undergoing a two-month program with sex specialist Chris Donaghue.  The participants are male and female, gay and hetero, range in age from 20 to forty-years-old.  They attend a group therapy session with issues ranging from dangerous promiscuity to clinical frigidity, from violent sex addiction to compulsive public sex.  Under his supervision in the sex therapy group program they'll finally address their deep-rooted issues around sex, infidelity, trust, relational intimacy and sexual addiction.

List of Hardcore Pawn episodes: "Hardcore Pawn" is an American reality television series airing on truTV that follows the day-to-day operations of American Jewelry and Loan, a family-owned and operated pawn shop in Detroit, Michigan's 8 Mile Road corridor.  The series, which was preceded by two pilot episodes in 2009, premiered on August 16, 2010.

Supporting paragraphs: Counting Cars American Restoration
Answer: American Restoration