I got to thinking a bit more about this. Technically the gun may not be deemed as 'out of proof' as the law requires that it cannot accept a plug guage above a certain size. Maybe the Proof Laws do not apply in this instance. As long as the purchaser is aware that the gun is damaged or deffective then there is no deception on your part. Of course there is always the way around it by just selling the stock, action and forend and then giving the barrels to the puchaser but for self protection have a paper signed to the effect that all except the barrels were sold. Guns out of proof can be given, they just can't be sold or offered for sale.
Nial, these laws were brought in by the Gunmakers themselves by lobbying Parliament. It is there to protect the Gunmaker and the consumer. The good thing about it is that we can send a gun in to be tested to be fairly certain that it is safe; not in this case but such failures after proof are extremely rare, rather than rely on the word of someone visually examining the gun and giving their opinion it is safe. We have the same system of Hall Marking gold and silver to be assured that it is of the right quality in order to protect the purchaser. You will find that the Proof Laws are very much supported here by shooters. Lagopus.....