Evening Jim, thanks mate, pm back in the morning..
Hi Dan, many thanks for giving this such serous thought, great idea and one I will certainly consider..
Here's the thing, the receiver is effectively the rifle and the Canadian inch pattern is a quite a different cut, so though it might well be an expensive undertaking, I would like to build a straight pull with a complete set of C1 parts (except barrel), if an old spec style deac has been carefully done, (and assuming stripping and adjusting such a thing is legal to do in Canada) it could be stripped by a gunsmith, receiver repaired and shipped to the UK as a Sec1 kit along with a bolt group.
The easiest thing would be to send the deac complete, but that is a potential legal minefield and in my experience, it pays to have paperwork proving your build started as a sec1 parts kit....a case of belt, braces and tin hat to keep big brother at bay!
With our crazy mixed up gun law here in the UK, it would probably be regarded as sec5, thus retaining that status no matter what you did, short of welding it into an inert lump of steel!
I would go down the substitute receiver route for my proposed future L2A1 build, that would be a Lithgow L1A1 receiver ( I know they are the same bar the markings) but I think using a former LMG receiver would be a step too far for the powers that be chaps..that just might make them blow a gasket!
I will cast the net for an old spec deac L2A1 for the collection and for barrel measurements... The L2 gas block and tripod assembly might be tricky to source I suppose..