If the barrel weight is less than 2% of as marked at the time of proof, the gun was considered out of proof by the Liege proof house
As Mike observed it was reproved after barrel honing.
RIGHT originally 18.3 mm = .720" opened to 18.4 = .724 with choke 17.4 = .685 = .039 or Full.
LEFT originally 18.2 = .717 with choke 17.3 = .681. Opened to 18.3 = .720 with choke 17.1 = .673 = .047 or XF.
The
current bore dimensions and wall thickness are critical.
The gun could be an excellent value. The problem with pricing is that used by not abused Field grade Belgian and U.S. maker guns are coming out of closets in droves as "the greatest generation" passes, and the number of those interested in vintage doubles is diminishing.