Hi,
Right, 84 was silver standard in Imperial Russia for .875 fineness.
The spoon was assayed in Moscow / town mark on the right is St George Moscow assay office mark, see here:
https://www.925-1000.com/Frussia_city_01.html
In maker`s initials (mark on the left) the first letter cannot be deciphered, making it difficult to identify.
Will try to sort out possible candidates with family name started with A.
Regards