During my trial and error process of replacing the rubber bands in the action figures I found two O-rings that I like to use. The black neoprene O-rings with the 5/8 in outer diameter fit perfect like the original, so I used these for fixing the G.I.Joes that I passed on to my son. The green O-rings with 5/8in inner diameter fit well with less tension than the black O-rings, I used the green O-rings for fixing the joes that went onto my shelf for display.
I would not have put together this instructable if it were not for being inspired by a fun instructable I read by M.C.Langer https://www.instructables.com/id/Fix-a-classic-GIJOE-figure-using-a-condom/
Step 1: What You Will Need.
1980's vintage G.I.JOE action figure.
5/8 inch automotive O-rings.
Small Philips screw driver.