In 1987, or thereabouts, the Gunsite Gunsmithy began offering a simple M1911built to Jeff Cooper's specifications. These original Gunsite Service Pistols, or GSPs, were built on Springfield Armory parts kits. They were fitted with high visibility fixed sights designed by Robbie Barkkman back when he ran the Gunsmithy. The trigger was tuned to four pounds. The hammer was slightly bobbed , an extended thumb safety fitted and the rear of the gun was dehorned. Basic reliability work was performed. An oversize firing pin stop was pressfit and a thick-skirted, oversize barrel bushing was fitted. After meeting the Colonel's approval, 'GSP' was engraved on the right front of the slide. Cost in 1987 was $575.
Pic of a later model GSP built on an actual Springfield Armory pistol [instead of a parts kit like the first 100].
Shortly after I returned to Louisiana in 1992, I contacted Robbie Barkkman and made arrangements to ship a Springfield Armory M1911 to his shop to recreate a Gunsite Service Pistol for me. I carried that RoBar GSP for several years until switching to Glocks. I gave my GSP and a set of Milt Sparks leather gear to a friend when I left Oregon in early 99 and haven't owned a M1911 since.
A few months ago, I got an itch to add an 1911 back to the collection. Specifically, I wanted to recreate an old style GSP. According to a passage from a 1989 vintage Gunsite Gossip, Auto Ordnance became the supplier of the base pistol when the Springfield kits were no longer available. As fate would have it, I managed to obtain an Auto Ord M1911 from a forum member and the 'game was afoot'.