I agree.
There is a board member from Italy who has great insight into translating the Latvian markings - I'll see if I can dig out an old thread that he contributed to....
I agree.That is a very nice Finn-acquired/ Finn stocked Soviet 1891/30 rifle you've got. The letters along the side of the receiver look like those odd Latvian/ Lettland marks that show up every now and then. A cleaner close-up on "macro" on the camera might help. My sense is that is what those are. Probably one of the 91/30s supplied by the Germans to Finland during the Continuation War and then [SA] Finnish army property marked.
Nice one!