Postby AG2012 » Thu Aug 06, 2020 1:52 pm
Hi,
The mark was used after 1927,meaning not Imperial Russian but Soviet period. Alpha is for Leningrad (St Petersburg).
Circular mark is secondary mark (it looks overstruck over existing mark).Rectangular mark is maker's mark - difficult to decipher, most likely one of state owned factories.
The technique is called samorodnoе (самородное) meaning native silver.
Irregular surfaces are made by heating silver sheet close to melting point until silver starts to warp.The result cannot be predicted; sometimes not very successful aesthetically.Your example belongs to post revolutionary production when the quality sharply declined.
Regards