Oblique hammers

[Stéphane Collin]

Hi List.

I recently serviced a small Pleyel 5'2" piano from the '30.  It had the most charming sound I ever heard (a real miracle).  Up 'till the last trebble notes were singing with unusual beautiful tone, long lasting and very dynamic.
It featured something I have never seen before : from the tenor to the trebble, all hammers were filed a little oblique, so on a light blow they hit only one string, but not too much, so on a hard one, they hit all three strings.  The result was incredible.  I suppose on a hard blow, the hammers stay less in contact with the third string of the unisson, letting more overtones develop, while the longer lasting contact with the first string of the unison gives full power and sustain to the fundamental of the note, the blend of both making this unusual beautiful expressive sound.

Has anybody seen this before?

I couldn't wait and try this on one of my pianos, and with happy result : unbelievable pure and sweet pianos, yet very colourful and powerful fortes.  It doesn't work on the low tenors, neither on the high trebble, but elsewhere, waw !
I'm just afraid for premature wear of the hammers and maybe some trouble at the flange center pin, carrying so an unusual torque.  Also, I believe if someone notice this on one of my pianos, he will believe I am an outrageous piano destructor.

Any comment welcome.

Stéphane Collin
(Brussels, Belgium)