Shulze Pollmann and various problems

There, leveling finished, re-checked escapements and hammer regulating again... I searched the internet for straightening, I found videos with a specific tool, but nothing with normal iron.

For

For the voicing, take a knife with a flat stainless steel blade and heat it on the gas stove. It must not be red hot; you must be able to touch it without burning yourself.

Once heated, place it on the two sides of the hammer applying a little pressure; I recommend "rocking" it across the entire surface, first from 9 o'clock to 12 o'clock and then from 3 o'clock to 12 o'clock (counter-clockwise).

The action must be placed on a bench with the hammers facing upwards (i.e., placed horizontally).

When the blade cools down, heat it again; just a few seconds are enough. You must not burn the felt.

Ciao

So Giovanni, I did the ironing [string stretching], but the sound has remained dull. In practice, the whole series of strings. Could it be that these are exactly what lost elasticity after 30 years?

It could be the strings, but 30 years is relatively little for a piano.

Of course, changing the strings is an expense; first you must be sure, you need to hear them, you need to try winding them in the opposite direction to see if it improves.

The hammers have surely been mistreated as well and should be replaced; you could try soaking the bass hammers and see if it improves. And then you can leave it like that without spending money on it, it's not worth it.

Yes indeed, thanks again for all the advice; maybe in the new year I will show it to someone more experienced. For now I am busy with tuning, perhaps I will post in the appropriate section

Eh, the verticality yes, then all these measurements depend on how the action was positioned in the factory