"My question is, would it be advantageous it to spend the extra money for a correctly numbered lock bolt and side plate? And if it would any resale value to it. Is anyone run across 6"barrels with no visible identification?"
Answers to above:
No;
you already have what it is worth in it or on order, IMO;
Yes, aftermarket commercial barrels.
You might have the same numbers on the parts, but they will not be "matching"; and matching "except...." is being like a little pregnant.