Lancaster
You’re right, it seems to be a customized MAS 36. Not a poor picking, a common cheap and sturdy rifle, with parts aplenty available. Just like the 303 for the English hunters.
When in the army I used this rifle for ward duty and parade. We weren’t supposed to deteriorate the strategic stocks of serious weapons……………………and the FAMAS, FRF2, PGM and MINIMI weren’t invented.