I made some rectangular loops for bra hardware. You could scale and resize aspects to work for crossbody bags as well. Default size is for 3/4" width notions. Modelled in Tinkercad.
(Ignore the crappy sewing on the bra, I'm learning okay!?)
Use freely!
rectangular_loop.stl | 2.8KB | |
rectangular_loop_w_crossbar.stl | 3.8KB |