I have searched the forum and the internet and I found 100s of posts and or questions about couplers, but none answered my exact question. I searched MTL’s website and still didn’t get my answer! So either I can’t explain it right or what I’m looking for doesn’t exist but I sware I’ve seen it. So the question is a couple parts. First off I have 99% rapido couplers and most of, if not all are truck mounted. I have a few places on the layout with hard to reach places. By the time I get the cars uncoupled it looks like a horrible derailment scene locos and cars on their sides scattered everywhere! Everything off the track etc. So to fix that problem I took a little tiny switcher and cut the hook part off the coupler so I can push cars to these locations and then back away without pulling the cars back. Then I get them with an engine with an unmodified coupler. Everything seemed ok. Then my son in law bought me a new fox valley models NS engine and six cars with knuckle couplers. Now I have two different styles. That’s the first part of the question are all knuckle couplers the same? If not will they couple together? Then the main part of the question is, do they make a knuckle coupler that has that t shaped shank like the rapido that will mount into the rapido “box” with no modifications. I want to say I’ve seen them on the internet but I can’t find them again. I really don’t want to have to replace all my trucks if I don’t have to. I know I can make an adaptor car but I rather change everything to the same coupler if it’s reasonable. Thanks for any help and or advice.