It was Marks_21 that discovered my secret .... now that the cat is out of the bag. .....
This has been a fun posting .. and yes ... I did actually cut off the barrel(s) and obtained an NFA license for a short barrel rifle. I called Holland and Holland, and a set of replacement barrels would cost $40,000 pounds - that's $52,000 in U.S. dollars, and 2 years to complete the new barrels. (I'm 75) My hacksaw was free. So now the fun is over, and just like Paul Harvey's Radio Talk Show,
"... Now you know the rest of the story..."SEE THIS LINK -
https://www.gunbroker.com/item/1149509900 I have now told the whole story, and have enjoyed all the criticism before doing so.
Apparently the gun was blown up many, many, years ago when trying to regulate it for U.S. loaded ammo. According to the lady that consigned it for sale ... after it blew up, her Great Grandfather put it away, and her Grandfather never did anything with it either, and neither did her Dad, (who passed away) and then it sat for many more years until she sent it for sale. I think the high cost of replacement barrels back then prevented the repair. Current cost for Holland and Holland to make a set of replacement barrels is over $40,000 pounds ($52,500 U.S. dollars).... and more than a 2 year wait.
If I had to guess what happened, the left barrel was fired first, and the recoil dislodged the bullet from its case in the right barrel, which acted like an obstruction when the right trigger was pulled, which blew up the barrel. Copper fowling at the muzzle was evident in the left barrel, but none in the right barrel. Other than the blown up right barrel, the gun looks nearly unfired, even "Mint". Not even a hint of brass transfer on the recoil shields.