A guy I used to know used a repair kit on a seat and it worked great, though I remember him bitching that two of the repair kits he got made more of a mess than they fixed - luckily he was a cautious SOB and patch tested the underside of the seat before making a mess of things. That's going back quite a few years (hopefully things have gotten better) and I have NFI what he used that worked.

I'd try and check out their work. I doubt it would look as good as new, but you don't want an ugly patch on your bike...