Sorry for the long silence. Been real busy plus wanted to have something solid before posting.
Below is a pic of the profile and mesurement of the t-track I broke off from the cabinet in my house:
As you can see its bottom is very uneven. I thought this could be due to degradation from being there for over 20 years or so, so I decided to find something more recent.
I search every shop that sells anything related to furnishing fixtures in my town and after countless wild goose chase, false leads and similar t-track which are too small, I finally found a company which has a few strips in their inventory which matched the one from the cabinet from my house.
It comes in strips of 8 ft length, is made of rather rigid plastic/rubber, but is pretty flexible nonetheless:
Here are the mesurements for the new track I found:
There only 2 things that don't match: The groove on the bottom, and the color. The one I found is a reddish brown, not black.
Don't know if this track is anywhere near anything screen accurate, but I sure have more then enough grips now for all my custom sabers, if nothing else.