Thin loop on arm broke

The thin loop on one of the arms broke off and I would like a replacement. Where can I get a new arm?

I’ve broken the thin loop too. Repaired it using this part (Wm's OpenPPG Batch 3 Build Log Photo Album - #54 by 1066) and it worked really well. Going to do it on both bottom arm supports.

I already cut my hoop like glider pilots.