Hello all, I would greatly appreciate any guidance on this please. I'm looking to try and build some hopper cars, after some initial 3d printing tests have shown potential. So far, I've found some trucks made by 'Full Throttle' which have knuckle couplers. I have ordered two used marklin steam locos; though I'm unsure what type of coupler they have. I plan to add an AZL mikado to the mix before too long. From what I understand, there's several different types of Z scale coupler out there, and not all can be decoupled using track-mounted decoupler systems (which I would like to use in my layout). Is there any solution here which would let me run the Marklin locos, AZL loco, and all home-built railcars on the same type of coupler while retaining the ability to decouple? Lastly, I have not been able to find single wheelset mounts anywhere. Do these even exist by themselves? I would very much like to build some two-axle open coal cars for the smaller locos, in addition to the four axle larger coal hoppers for the larger locos. Any and all advice is greatly appreciated, thank you.