Just in case you wonder on what kind of piano I'm playing.

Getting information about it was very difficult because of it's age.

Here are some facts:

It's an upright Karl Hamburger piano which was originally built between
1880 and 1900.
It's significantly taller than today's standard pianos which results in a richer sound similar to the grand pianos. The strings are fixed on a heavy iron framework and are strung crossways.

It was repaired and restored by my mother's grandfather as it was a present for my mother.
It's been tuned in 2007.

The Piano would need a lot of repair and replace work to get it's orignial, brilliant sound back but that's way too expensive for how often it's used ;).