Gunmakers in Tula very liked high comb on any gun they made and it doesn't mean it was trap gun. I believe it's MC11-12 hunting modification and stock could be straight English, with high comb or Monte Carlo. Weight 3,5-3,75 Kg. Seems previous owner hated high comb and cut it off. Chokes are of parabolic shape and guaranteed distance for killing gamebirds till 50 meters.
Parabilic chokes was headache on East German o/u Merkel's, 'cause it was ligher guns with not enough metal on barrels, but it was good for MC-11 and most wanted for goose hunting. Unfortunatly today it's not possible to use it with steel shot.