[Mr70]

Don't feel bad,although your hunting feverishly for ones specific to your car,you may never find them because they don't exsit.Not every single car dealership had License plate frames made up for themselves.It was at their own discretion to order them from an aftermarket company back then & was rather expensive,so many did not do it all.It depended how much profit/risk a dealership was willing to take on back then.
You can get a custom made License plate frame nearly anywhere today,in both chrome metal & hard plastic,but they use todays technology like lazer etching or a hard vinyl applique respectively.Some of them look cheesey and not at all close to what the originals were 40 some years ago.
Type in "custom made license frame" on the eBay search box and you'll see hundreds of design ideas to choose from.
The usually charge $5 each,and although not at all like some may want,they are very inexpensive compared to the vintage frames most desire.
Hiring a company today to tool up for the vintage potmetal chrome ones would be extremely costly for the final outcome I would think.