Bridgestone used to make 135mm pitch rubber tracks for the Mitsubishi/Komatsu 4 tonne crawlers.
After a while,they tore themselves apart. If they held together,they would lose traction after loading the blade half way.
Perfect for trimming up Golf Courses,etc,...but useless elsewhere.
Not sure if anyone made rubber tracks to fit old dozers like the TD6.
I have seen pictures of TD6 with add on rubber pads for special works,back in the 60s.
Try the REDPOWER FORUMS & see what you come up with.
In Australia,we had both TD6 & BTD6 (British) . The BTD6 had a 264 diesel,no gas start.
I always thought they pushed well for their size. Still many running around on farms & blocks.