I may have one copy left of the CanadianOrdnance Corps, Extracts from Instructions for Armourers that details exactly what needs to be done to set up everything on an SMLE from scratch. I'm lucky to have purchased hundreds of SMLE spares many years ago and am lucky to be able to select fit from bins of parts as you describe. It can be very time consuming but not that difficult. I can't imagine just slapping one together like an AR15 which any garage gunsmith can do. Working these old rifles is a real world learning experience. It's easy to make them pretty but not so much to make them fit and function correctly. Email me at bdlltd@bellsouth.net if interested and I'll see if I have one copy left. I still keep a clean one in my reference library and an ugly, greasy one with many handwritten notes on my bench but I seriously doubt I'll ever have them printed again as too many folks just don't buy books anymore thinking they can get everything they need as a free download off the internet.