I have a minty MAS 45 example but it's just not my favorite .22 trainer no matter how much I want to like it considering it's stolen, ahem, borrowed, German lineage.
I'm not really a fan of that particular peep sight nor the more broad, as opposed to narrow, front sight found on the MAS 45.
For me, the V notch on the German .22 trainers is superior in regard to accuracy even with them having a shorter sight radius than the MAS 45.
Oddly though, my '60s era Walther .22 match variant (not sure exactly which model) with its Walther branded diopter sight, a form of peep, is easily the most accurate rifle I own.