I love working on Bosendorfer pianos. Now owned by Yamaha, Bosendorfer is a truly great European instrument, and I have the privilege of working on them regularly.
The Bosendorfers from the 70s and 80s did have a particular issue that is often mis-diagnosed and very often mis-repaired. If you notice that your older Bosendorfer is not holding its tuning all that well in the bass or that the bass notes have a ‘clicking’ sound when you play, you might have one of the models that suffered from a lose pinblock. Not to despair. I have been trained by Bosendorfer on how to permanently correct this issue. It takes about a day and a half, but it can be done in-home without moving the piano to a repair facility. I’ve done repairs on these pianos in Ontario and Manitoba. I’m waiting for the call to Bermuda.