Tom, IMO, its value is set at this point. If you did want this particular gun, then you need to get a good valuation and be sure said valuation properly discounts the cut barrels. Then, you can resell and recover (most of) your money.
Do note that there are plenty of Brit guns out there in a very active market. Do not fear missing out on a bargain; those are few and far between. You are far more likely to get stuck with a dog than to pick off a bargain - especially if you get in a hurry.
What would be the purpose of a Brit gun for you?
DDA