Gentlemen,
I assure you the English, Australian and Canadian shooters/collectors are familiar with US laws. You need not make comments on how easy it is to buy and hold arms in most of the United States, this is well known and at times comes across as “crowing’.
In the end the deactivated arms do serve a purpose, they allow folks to own arms that they could not hold otherwise. This is equally true in the US regarding classes of arms you cannot freely purchase, you cannot buy an M16 that works as designed for less than 12,000 dollars and in many states you will not be able to obtain the permit for it. The UK has military arms available that the US collectors can only dream of, albeit in deact configuration. It is possible in the UK and Canada to get a deact MP44, Vickers, MG-42, and pretty much any other arm you would like to have with all correct parts, which anyone can buy and hold. True it will not fire, but they can be stripped and the mechanism examined along with the correct historic markings. The cost is moderate enough to allow a representative collection to be put together. You cannot do that in the states with automatics or arms not approved for import, the action body has to be solid and made of some other material, as the US has a policy “once an automatic, always an automatic”. The cost of original live automatic or destructive device arms available in the US is such that very few have deep enough pockets to own more than one or two of such patterns. The US has more severe regulations regarding other deact weapons than is the case in other parts of the English speaking realm. The fact that reasonable collections of deacts are being put together in the UK and Canada at least ensures that some semblance of these arms survives. The fate otherwise is to be made into manhole covers or the equivalent.
All arms have an effective life. At some point all tools become artifacts. In the end these historic arms that many enjoy and shoot today will be regulated to the shelves and walls, rarely to be fired under any circumstances. The numbers of American civil war arms that are still being used and actively fired are truly small, those arms are now almost entirely too valuable to be fired for fear of damage. Those of the American revolutionary period I do not believe are ever shot, having far too much value and rare. The age of the American revolutionary arms is around 225 years old; those of the American civil war in the 150 year old range; many of the Enfield rifles are in the 100 to 110 year old range. It will not be more than a generation or two until these arms see a similar pattern of use, once surplus ammunition has evaporated and the generations that had a primary connection to these arms are gone. As time proceeds they will be replaced by whatever the shooting public is allowed. The fact that automatic arms were preserved in this generation by being deacted will be a godsend to collectors in the 22nd and 23rd centuries, assuming that some semblance of western civilization survives.
Now I am sure that we would all like to live under a system where we could collect and shoot small arms to our hearts delight. The US certainly does enjoy far more access to collectable long arms and handguns, as well partially functional copies of self loading military arms. Many do not have that liberty and make do with what they can, in those cases the Deacts serve such a purpose.