I'm tracking down parts for my Yamaha and was wondering where the best place to find a rear fender (just the metal I have the inner plastic), rear brake light, front and rear turn signals, rear rack, and bolts/mounting hardware for the rear fender.
also, what should I be replacing on this bike regarding seals and such. It's been sitting a very long time without running...

I thought that Ebay used motorcycle parts had one just today. I check first thing every morning on weelends.

Just checked again, the rear fender 360/400 out of Montana, $168.00 free shipping.

Holy cow that is expensive.

I found a local 1974 dt250 rear fender. Will this fit my Dt360?

Yes it should fit.

Partzilla lists them as the same fender, the same part number. So yes, it will fit.

Cool. Thanks for the help guys. I heard somewhere that the dt250 might have a different angle that the tail light mounts up on. Is this true even with the same part #?

As a general rule, if you look up a part on CMSNL and Partzilla, they will show which other models used that part. In this case, the DT250,360 and 400 from 1974,1975 and 1976 all used the same rear mudguard and rear light.