Complex sentence: About 400 of the Second Generation Colt Single Actions were factory engraved by Colt's, the factory engravers of the period were Alvin Herbert, Earl Bieu, Dennis Kies, Robert Burt and Leonard Francolini.
Split into simpler sentences: About 400 of the Second Generation Colt Single Actions were factory engraved by Colt. The factory engravers of the period were Alvin Herbert, Earl Bieu, Dennis Kies, Robert Burt and Leonard Francolini.