Hard to guess, Lou. You know what they say- it's worth whatever someone is willing to pay for it.
More information on the re-barrel work would be helpful. Was the receiver fully blueprinted by the gunsmith before the barrel was installed? Specifics as to the work done are relative to the value, particularly if receipts(s) back it up.
The problem is that you can only demonstrate a best group of .6 moa- which isn't the real standard used. It's what the rifle can consistently shoot...
Granted, you're handicapped by the fact that you didn't use match-grade bullets, and didn't do extensive load development.
If you had a load "recipe", together with a five-group, five shot each target all showing sub half-minute- it becomes a "proven" shooter rather than a "maybe", and the price is affected accordingly. If you want top dollar, it would behoove you to try to work up the most accurate load for the rifle.