Hi Garbone,
I think you may have a unit 250 'Clipper' there [iron head], but it is a bit murky where Clippers / early Crusaders are concearned. Another possible giveaway would be a half width rear hub and 6" front full width hub. I have a few like this in simillar condition, all but one of them run, but are awaiting their turn to be sorted. One that I have has only covered 13,000 miles from new [the non runner] and was only used for a year from new, apparently, before it was traded in at a local bike shop, where it stood in an outbuilding with a Tiger Cub [which I also bought], the building fell down on them and they languished for 30 years or so, before i got them. The Enfield's rotten spokes were collapsing as we wheeled her out, the seat was rotted away and the tank rotted through. the engine turned and had clean, green oil in it, enclosed rear chain is like new and the speedo responds when the rear wheel is spun. VERY RUSTY, but not beyond salvation one day!
Good luck with yours,
B.W.