Hello everyone,
I have the dust cover against the seal now thanks again for the help. Just wondering if I don't have the bearing and seal in far enough because when I look at the lug on the lower fork engaging the brake plate it's not seated fully and the tire doesn't look quite perfectly centered on the fork brace , any thoughts greatly appreciated as always.
  

I'm thinking that if you loosen up the two nuts on the bottom of the right fork you should be able to get the axle in all the way then you'll be able to work the brake arm in some more.  Those two nuts are the last thing I tighten. 

EDIT:  The brake arm bolt should ride in the grove, it can be a pain to work the arm onto the other side but it will go.

Thanks for the info , will give it another go tomorrow after work

The 1975 Dt250 FOTO1971 Rotor, the one without the machined edge , fit my 1974 dt250 model ,has no clearance issues and is working great.