Fogive me if this is too-oft-asked, especially if by me... I've got a small pile of old, mostly cheap HO cars - TYCO and the like - that have horn-hook couplers. I'd like to swap them out for Kadees. Is there a single standard "drop-in" Kadee coupler that I can use, or am I going to have to look up the make/model of each car and find the right one? I'm not terribly concerned about getting these cars super-prototypical or anything, I just want them to function and have knuckles. Thanks!