Anyone know the make/model & possible value of my Russian piano accordion. Has the first letter missing, but looks like it was a russian B, which if im correct spells Boreas ? I know value is all about whats inside. All keys/ buttons & registers works fine, seems in fine tune, reeds, wax & valves excellent. I have scrolled the net (uk) & cant find any info on Russian piano accordions, only button accordions. Any help would be appreciated.