Check to see if Reno has a historical society. If they do contact them as they may be able to tell you more about the dealership and what kind of things they had.
There was quite a long discussion on this forum about license plate frames. IIRC Don Rush at West Coast Classic Cougars had a contact who made reproduction dealer plate frames. A quick search on the forum would probably give you the information you need.
I personally found some old local dealer frames on eBay.
Thanks for the responses. I have been following Ebay, and attempted to contact the Reno Historical Society. It’s basically closed until December for a two year renovation/remodel.
I contacted an autoparts store in a wild a_ _ guess. Very interesting conversation not entirely related to my search. He suggested a Ford dealer who in turn recommended a restoration shop. I’m waiting for a possible response as they have a part time employee who worked for a Ford garage 27 years. Long shot….
Sierra Lincoln - Mercury went out of business 15 +/- years ago.
Also checked with several junk yards. Put a part request on Auto-parts.com. Not holding my breath here.