Thanks a lot Phil.
They are old as you say. They come in an italian PCB which has a 89C52 uC... oldie, right?
It seems that my boss has found them. He will get them tomorrow and we will see if they fit and have the same dimensions.
About the buttons on the link you found, I saw lots of them yesterday while browsing 250 pages in Mouser... my eyes were hurt at the end. Thanks for the link anyways.
I will tell you tomorrow if my boss actually gets the buttons so that nobody else keeps looking for them in vain.
Omron A3AT-9 maybe??
Close, pretty close. Maybe Omron has a similar model. Thanks!