Just got my prints and they look great. All arch bars and the rivet detail printed fine in FUD. Your bolster pin is a nice friction fit on a MTL underframe (using the 36' reefer w/ truss bars).
I do wish you had offered this in FXD as I do have some surface prep to do. And also, in a prototype picture I have, the bottom arch bars between the journals and the bolster bar appear to slope UP to the journals, not DOWN as in this model. And it has me wondering if you made some compromises for track & car clearance and/or took your measurement off an loose truck (unsprung, as it was not weighted by a boxcar & load).
Finally, my car diagram - which admittedly might be a slightly a different version of this truck - calls for 60" to axle center truck. As such, in part due to these wider trucks, they hang ever so slightly over the end sills of this MTL car underframe (and likely flush with the boxcar endsill once such is added to the frame.) (In my prototype diagram, the end of the brake bar is 6" from the end of the endsill. So a 6" scale narrower truck would give some of this back, it would still require a 3" scale mod to the MTL underframe to nail the prototype diagram.
I bought these trucks for the brake bar, and am very pleased with this detail which roll free of the MTL stock wheel set.