So I have just finished cutting new foam (wore out the 70's turkey knife-need to replace for thanksgiving) and am shopping for someone to re-upholster. I was originally going to go with denim to go with the yellow interior, but have been advised against cotton, so I'm now shopping for proper fabric. I am wondering what the deal is with the vinyl on the bottoms.

I was told it was to protect against moisture, and that it was used b/c it was cheaper than upholstery fabric. Anyway, when I ripped off the old covers it was only the vinyl that had mildew, I'd assumed it was b/c the vinyl wasn't breatheable. I need to decide what and how much fabric to buy and was hoping others would have suggestions on this. I'm not to keen on vinyl now after seeing all the mildew on it. Thanks