Fender Tag Missing

Nope, I don't have a broadcast sheet either...part of the VIN code states that the car is a 340. The car isn't matching #,but has "year correct" engine,carb.,paint color,interior,etc. As far as resale value," very nicely restored" w/o tag is $12,000. and "very nicely restored" with tag is $15,000.? Does that sound about right?