Key points:
The only legal way to sell or give away a UK-spec de-ac once the ban comes into force will be to have it re-deactivated to the new EU spec, which involves welding the firearm solid.
Sources in the historical reenactment world have told UKSN that some groups are apparently considering whether to ditch de-acs and simply invest in live firearms instead, as it makes international travel for fully-equipped reenactment groups easier.
I am actually fully in favour of this opition

Just a thought, it regards to re-enactors, have any of you actually considered what your Great Grandfather or Uncle would have to say about meeting you dressed in the correct period uniform, gas mask, bayonet etc. every last little detail correct, when he asks to see your Lee Enfield Rifle.... you hand it over and he says "what the hell have you done to this!?!?.... You've welded it up and totally destroyed it" ..... I can imagine my ancestors being rather annoyed! They may well feel you have dishonoured them and the rifle they relied so heavily upon.
I'd rather go without a rifle if a Deact was the only option. Thankfully I have an FAC and have owned a fully functional SMLE ....