“Brothers Diederichs” Factory, No. 17239.
Russia, St. Petersburg, around 1910

“БРАТЬЯ ДИДЕРИХС DIEDERICHS FRERES 1810–1910 (Brothers Diederichs 1810–1910)” — a round stamp by black dye on the frame;
“GEBR. DIEDERICHS” — a cast inscription on the frame (area of the tuning pegs of the descant register);
“17239” — a stamp by black dye on the frame (area of the tuning pegs of the bass register).

2343×1475×367
Wood, metal, bone, fabric, felt

1970s, arrived from an unknown source
Stock number: 23552

The frame is cast iron. There are 2 pedals.
The case is tinted black.