Got the floppy drive out of the T4700CT because I knew the driving belt was too loose, the motor spins but the disk does not. It is still in one piece and not gummy at all, but it is indeed stretched.
The rough measures are 220mm long by 1,5mm wide and 0,5mm thick. It is a flat belt, not a square one as you can tell by the numbers.
Now I am on a quest for one. Also will be cleaning the old grease, as the mechanism was a bit slow when I was ejecting the disks.

As far as I understand I should use silicone grease for this kind of purpose, since is in touch with plastics also. Is that correct? Would you recommend any specific one?
Does anybody have any info where to find the right belt?

Thanks!

Martin