I have a DR500 1983 model ,it has 1982 rm 250 front end they have 38mm forks less chance of bending these instead of the DR ones, but you will have to press the centre shalf out of the org DR bottom triple clamp and install
it in the rm bottom triple clamp because of the diffrent lengths, this is to fit the RM triple clamps, but i run the org tank and seat on mine
The RM 250 84,85,86 rear wheels will suit the org DR500 alloy swing arm because these wheels run the right size axles to suit the swing arm ,,and all these RM wheels have the same part numbers ;)but they only have 130mm brake hub size than the org DR wheel being 150mm,but the rm wheels are lighter
I would post a pic but havent got this far on the forum