I had a Parker VHE that had been customized into a target gun. Restocked, some engraving, choke tubes, etc. In the case of a VHE 12ga, there's not huge value anyhow unless it's in near perfect original condition. So in that case, the value increased . . . but I don't know how much the custom work cost. Enough to offset the price of the post-customized gun? In that case, maybe so.

I just had occasion to look at a Fox A Grade 16ga, 32" barrels. Gun is in very good original condition . . . except for the fact that all choke was removed! Installing Brileys is about the only way to make it into a useful shooter. But whoever had the choke work done significantly devalued what has to be a pretty darned rare gun.