Here's a question which might be anathema to some of you... retrofitting postwar-style knuckle couplers.
I know LTI released the 6-18000 in 1989 which was made from the prewar switcher tooling and it had knuckle couplers. As far as I know this is the only reissue. Were any other changes made to make this possible? Were these knuckle couplers unique to 6-18000, or can couplers from a postwar 0-4-0 like the 1615 be used? Thanks!