So I got a TTR250 front brake system complete with caliper, line and MC off ebay. Cheaper than buying a rebuild kit for the 91-94 KDX250 MC.
Well the caliper is the same, just a newer casting nissan unit. Remove it from the TTR250 anchor plate and it slides onto the KDX anchor plate! The brake lever on the MC also looks to be a direct swap. Best part about this is that the TTR has steel pistons vs the stock phenolmic units in the KDX!