I use Cathy’s Upholstery, in Smithfield NC. She has done several jobs for myself and my friends , and always does quality work at the best prices. I realize this is some distance from you , but thought I would share anyway.
her number is ... 919-202-4640
Micheal Sasser at Coastal Canvas used to make the OEM canvas for Parker back then, so he should have the patterns. This is assuming he is still in business, I know he was wanting to retire a while back. I will recommend him personally, as he has made me a bunch of canvas over the years.