Hopefully the Trailboss load you mentioned will do well in the M-1917. I use 12 gr and a 190 gr cast GC bullet in my '03, but my '17 doesn't like it. Haven't experimented too much yet, though. This particular bullet seems to have too small diameter in the nose section for the '17,but not for the '03 or 30-40. Actually, I've never had any success yet with any Enfield I own with cast, although I've never really worked much with them.
You probably won't need to anneal your cases, and shouldn't need to do more than neck size the first time just to straighten out out-of-round case necks common in bulk packed brass.