Pic shows the chain from a 1971 CB750K1. Hanging, the chain links will almost hold whatever kinked or bent position you put them in. One of the o-rings on the clip-style master link is split and the other three look to be a bit worn. So not sure if chain needs replacing, a new o-ring master link, or just four new O-rings. The best one I took off the master link measured 6mm ID, 10mm OD, and 1.8mm cross section. Wondering what is best course of action.