It's certainly not going to help it! The title is going to be branded forever and will always raise questions during a sale. I wouldn't touch a car with a 10 ft pole that has vin tag issues. NC is pretty tough about registration of out of state cars that are 35+ years old so vin tag problems make it even tougher.
The CHP will issue a new VIN, it will look like this:
It shouldn't affect the value much, if any. There are dozens of cars that get this every week at most CHP offices.
I would raise hell about that shop "losing" it, that's a pretty big deal.
I too had a replacement VIN on my '57 Plymouth. It was quite painless. Took the car to the CHP, they took it inside, and out it came with a replacement VIN.
Just be sure to clearly tell your insurance company. Mine questioned me about it a year or two later as the # differed from what they thought it "should be". After explaining it to them (again) all was good.