(sorry I just noticed this lost is 60 days old)...you e probably moved on! But here was my advice.
It’s not too hard to replace the vinyl. Buy it at a fabric store-make sure it’s marine grade. Make sure the vinyl is very warm and staple around the edges with stainless steel staples. Doing this in the sun or using a hair dryer will help you to stretch it around the contours. Remember...once you staple through it, you cannot “unstaple”...the holes will stay. So start with a few anchor points around the edge a little loose and gradually work your way around on both sides, tightening and stapling as you go.
Or buy a new cover that is already contoured. It will cost more, and you will still have to staple it on. But it will be a bit easier to do.
I have had very bad luck repairing vinyl. Getting the color and texture to match is basically impossible. And the rough conditions these seats go through are not ideal for trying to patch.