Ive had this for a while now. It has no crystal and - because of that - a filthy unnamed dial, no hands, and a mangled cannon pinion & possibly mangled centre shaft. But it RUNS!
I can't place it. Case hallmarked 1927, About 29.5mm - so maybe 13'''.
The little lozenge mark is very small. Sorry its blurred:
It looks like an M or W with curly bits appended - or a V with extra long curly bits.
Thanks for any insight.