I have an Australian delivered 1980 dt125 that is a project to work on with my son's. As always with older bikes like this parts can be hard to come by. 
Stripping down the forks revealed Zero oil and worn bushes in the fork legs. 
I have been able to order oil seals and dust seals but can't find the bushes. They don't even seem to be listed in the Yamaha parts diagrams. 
The forks are the same as dt175, hoping that someone here has a lead on where I can get them from.