I second what David said with the caveat that I have run into a few coupler conversions that were maddening due to the teeny springs I had to work with. The truck mounted ones were a snap.
Chris
I have a collection of n scale wagons and passenger cars of various manufacture most of which have rapido couplers. My locos are also split between 'the real thing' and rapido. Is there a good 'standard' coupler which 'fits evefrything' that will replace my rapido couplers the fitting of which is not too hard on old eyes? Makes a change not to ask about DCC!!
Peter