Hi, Just a quick tip:
When we bought our boat the dealer gave us a very wise pointer: Never, ever put the console cover underneath a full cover if left outside. The wind will quickly chafe the outer cover by rubbing it on the console cover. We have seen it done since, and it can really cause some nasty tears. Just a word of advice
Oh, and to the OP, I agree, look in Yellow Pages & find a local agricultural seamstress outfit