Hi Scott, in looking at the pic of your renzetti, I notice that the O ring is positioned to the rear od the vise head. When I purchased both of my renzettis, the O ring was placed between the first small screw knob and the attachment point for the vise arm. I don't know if that makes any difference or not in holding the hooks or wear and tear on the O ring but I replace my o rings from the front (pointed) head of the jaws. Have I been tying flies bass ackwards all these years?? The flies look OK!
Gerri