Large Tension Lock NEM Coupling

Most of my stock is equipped with Large Tension Locks, and the only design I found on here was ludicrously large for my use case. So when the opportunity arose, I bought a single pair of Hornby Large Tension Lock couplings to measure, and opened Tinkercad for the first time to create an (almost) exact recreation for 3D printing.

As the file names suggest, each part went through several iterations before being deemed satisfactory.

While the parts have been designed to pivot freely, They can't account for slightly dodgy printing. In which case, a drop of oil on the pivot point should be all that is needed to free them up again.

I'd recommend printing couplings in a minimum set of 4 to prevent deformation, with an extra hook or two to account for any that may ping off the build plate, fail anyway, or get dropped during assembly.

Assembly:

Using pliers, straighten out a staple, and insert it into the side nearest the hook, threading it through the hole in the hook's end.

Once you are