But….. there’s literally oodles of field grade model 12’s out there….they’re not collectors items, they were meant to be hunted and used.
I 100% support not altering a rare graded gun. Field grades are just that, meant for the field.

Having an additional barrel set fitted would be ideal, I agree. But sometimes it’s just not very practical (cost, parts availability, etc). The most economical and practical way to get that gun killing birds is to alter the choke for its intended purpose. Whether that means cutting a new choke, installing thin walls, etc.