It's normal size spoon (cca 60gr). My guess is Maribor/Mahrburg from Austria/Hungary. I hope someone can verify this, and maybe know the maker. Unfortunatly there is no tax marks, so it's unsure.
Although the shape of the hallmark would be without precedent, if it's not Maribor, the character M can refer Munkács or Miskolc. But this is a so much lesser possibility!
Any opinion interest! Thanks in advance!
Best Regards!
Krisztián