Well, these particular bikes are going on 30 years old. I believe I have a factory seat on the Avenger, and it's just starting to tear as well. Vinyl, even the good stuff, gives out after a while. Mine is tearing where my legs rub against it when I'm at a stop light. The rest of the seat is just about perfect, just 2 cuts along the front bottom of the seat.
So, when I get a little extra coin, I'll take it to a good car interior shop, and have them replace the torn sections. Should cost maybe $50-100 US. I was thinking of going to either a cover or redoing the whole seat in leather, but the replacement vinyl route may be better.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.