Unfortunately I’m unable to offer an opinion on a 30’s Niendorf.
However for your interest, we rented a brand new Gebr Niendorf upright piano in the late 80’s.
It was a good piano from what I recall, about a 116 size, very bright sounding with rather a heavy but pleasant action. I didn’t play at the time. This was to start our son with the local music school, and a rental piano seemed to make sense just in case he decided to abandon lessons suddenly.
I needn’t have worried, as he progressed well, after which we purchased the same piano, which took him all through conservatoire studies.
The piano was tuned once a year, and appeared to keep it’s tuning well in what I now realise were far from ideal conditions. Although never measured, there must have been some extreme seasonal highs and lows - both temps and humidity.
Our piano had Gebr Niendorf name on the fallboard, Gebr being the abbreviation for Gebrueder, meaning ‘brothers’ - unless I’m mistaken.
Also of related interest is that the same company Gebruder Niendorf GmbH in Luckenwalde, Germany, appear to have manufactured wooden propeller blades for aircraft during the war, then afterwards resumed piano manufacture.
As pianos and aviation are two of my passions, if anyone should know of any other piano makers who were also involved in manufacturing aircraft equipment, I would be interested to hear any details.
