That’s a brass warded lock from the 30’s,the Art-Deco period. Unknown maker.In it’s present condition it’s not worth much if anything. If it had the bale and wasn’t rusted out on the inside(springs) and had a operating key,it still would be worth no more than $20 on a good day. I like the green patina,and if I come across operating locks with that on them I leave it as is, It helps add to the value;-)
