Because the pair is old and the foam was ripping apart in bits, i decided to take act before that foam dust will enter and potentially damaging the drivers.
I took the pads off, removed all that foam and also some of the glue that was covering some of the left driver (now i know why it sometimes it felt as if the right was louder than the left!).
I've cleaned everything, and glued back a thin layer of material, to protect the drivers from dust. I also ripped all the heavily used leatherette from the pads, making them soft pads.
The Technics never was on the heavy bass side, despite its XBASS rating, it was fairly light AD700 like, now it gained more weight. It's still not heavy, it's less than HD 598, but has so much more texture than before. I'm very happy with the result.
A few photos. During the restoration procedure. (click on photos to see large)
And now after its done.
Not bad for a 7 year old headphone eh?