I can't say much about the barrel's appearance, but how much end shake and headspace it had could give you clues if anything was done to the barrel. It sounds to me like the rear of the barrel was cut back and the forcing cone not recut.
- Check the headspace at the rear of the cylinder. If it's about 0.065"-0.070", it's about right.
- Then check endshake. It should be nearly nothing, say 0.001"-0.003".
- Now open the cylinder. If the front face of the cylinder can move in front of the barrel rear by any amount, someone has set the barrel back one turn and then faced off the rear of the barrel to create a no-endshake condition not based on proper means. In other words, rather than stretching the crane and then fixing B/C gap, they have made it appear that endshake doesn't exist - I suspect for the fleecing of an unsuspecting buyer. Since the cut-off forcing cone has not been fixed, that increases my skepticism.
- If the open cylinder face doesn't move in front of the barrel rear, and the endshake when closed is acceptable, the barrel can be fixed by facing it off to correct B/C standards, and re-cutting the forcing cone. However, since that is an extra cost, his price is too high - offer him $800 if you're not sure about the barrel originality.