Junk yard's or specialty Car part Dealer's.Also try ebay and craigslist.You can also see if other part's from a different ford will work.A antique part's re-master take him the part's and he will duplicate,also fabrication shop's some time's can Re create car part's for rare car's!
A good place for parts is a company called LMC trucks. Check them out, they should have parts for your vehicle. If they do not, keep checking your local craigslist, bargain trader, swap meets, and ebay for the parts.