The silver backing was peeling off the mirror that was on my Spyder when I bought it. I took it out and went to the local glass shop where they may me 3 replacements for $20. (Their minimum order). I’d take a WAG that they could do convex mirrors as well.
A convex mirror the same size as the original glass, a few dabs of 3M Gorilla Snot, and Bob’s Yer Uncle.