I don't believe these type of items pop up here, but I thought I'd take a shot. I'm thinking it's for anesthesia?
The OP's mask is a single strap mask, has no provisions to attach to a helmet. With the one end of the strap riveted there is no way to replace the strap (Straps are high wear parts on O2 masks).
If this is an aviation related mask, it would be for emergency passenger use, or if aircrew used, the strap would go over the helmet, similar to WWII era masks.
It's made of lead, so is malleable. I read of an early version of a mask for delivering ether developed by Snow in the 1840's that was of similar construction. That's one of the things that mask me think it's more for medical use rather than aviation related.
It's made of lead, so is malleable. I read of an early version of a mask for delivering ether developed by Snow in the 1840's that was of similar construction. That's one of the things that mask me think it's more for medical use rather than aviation related.
That would make more sense to me. It could possibly be a vintage ether, nitrous oxide, or anesthesia mask. You could send an inquiry to the following link and see if they could help narrow it down. In the meantime people here will continue to look.
ANESTHESIA ANTIQUES: INHALERS AND DROPPERS