Not much meat with these potatoes

Sounds like a good plan to me.

Good luck

It's hard to tell from your photo and yes, the metal is thin.  But I see what looks like white or grey dots.  Any chance that your couplers broke because they are contaminated by Zinc pest?

Good thought. I got a second opinion on the picture (namely Gabe’s) and it would help to be sure those speckles are just white rust and not zinc pest. He couldn’t see any swelling, but the photo doesn’t show the fine details. If there’s a chance of the Sparkly Plague, you might need to reinforce both sides.

The part is so thin it has very little torsional/twisting resistance.

I'd suggest a 3D resin print with a tough resin, but still there is not a lot of twisting strength there, too.

This engine coupling is not CAT-RESISTANT!

PET-G or ABS might work for a printed replacement. PET-G is probably the better choice. There’s a way to pause print and embed either wire or (small) sheet metal, then resume, which might help.