I was able to find more information on the 1911 45 acp 6 inch barrel and new slide I did find this information in a search. MY barrel is just like this. has recessed target crown.
http://www.1911forum.com/forums/showthread.php?t=253207 and this comment "Interesting idea. Years ago there was a company that sold "drop iin" barrels with an adjustable slide stop (The name was Centaur IIRC). Instead of fitting the lower lugs, the slide stop had a slot cut into the top of the pin that held a small steel roller. You put different thicknesses of shim stock under the roller to adjust its height which had the effect of increasing or decreasing the diameter of the slide stop pin. Shims of different thickness were used until the barrel locked up and you could add shims later if the fit got loose - Same basic idea, just a different way of doing it.
Seems like a steal for just $125 plus actual shipping cost
ABLE
