This rare rifle is one of the only 500 Finnish M39/43 sniper rifles ever made. Note the “combination” of the German scope with the “German style SSR lever and pin” on the base with the “Russian style middle mount”.
Sniper Scopes
Sniper scopes from WWI to WW II
Sniper Scopes 
Congratulation on your collection pti nounou it s amazing!
Keep up the good work !
Thanks