Signature Series (3rd Generation) Colt BP revolvers were made by Iver Johnson in Middlesex N.J. under license from Colt. They were made from rough castings and unfinished parts supplied by US and European (Uberti) manufacturers, Colt had nothing to do with the manufacturing, inspection or marketing of the Sig Series guns.
Lou Imperato, DBA Iver Johnson did the F series of the 2nd gens.
Lou Imperato DBA Colt Black Powder Arms Co did the Signature series 3rd gen.
Lou Imperato was involved very early with the 2nd gens with Val Forgett and continued on with the 3rd gens.