Just got a free '76 MR250 (mint with 1114 miles). Anyone have general info on the MR 250? I've seen the 50s and 175s and find lots of info on them, but not the 250. Why is this thing so rare? As a kid, I remember seeing lots of CRs and MTs, but never an MR. Parts appear compatible with MT or CR. Any not so obvious differences? Anyone have parts or know a good source? Need both side covers, air filter with airbox cover, left case cover, and coil to make complete.