so, it was a Maxim/15, after all

.
Well, can't tell you much more than what you've said. The LMG version of the MG 08 was around since 1915 and in mass use since 1917. there were a ton of them around in the 1917 battles and it was extensively used in the 1918 german spring offensives...to track down where and how that particular weapon was captured is really really complicated just by the details of the weapon itself...
I'd say I agree with you too. Weapon regulations are really OK from my point of view, but for inoperable guns of historic value are rediculous. Ditto for airsoft "weapons", btw. and I agree with you too, that Machine gun is something worth keeping and to pass on within your family

.