it is a dubious buy for $200. The wheels and forks would be okay for RM, the frame if you look around the header pipe area has been attacked with a welder as has the kick start and gear shafts. The airbox looks okay but the appears rubber has gone hard and shrunk as usual. At least it is connected but not sure they even fit RM. Motor internals, electrics, carb, suspension, wheels, plastics maybe useful but yeah, being a trailbike it's bound to have seen lots of use and I would baulk at the price unless I was chasing the above mentioned parts specifically
PE250C engine parts below fit the RM's listed
clutch basket will fit RM250 A/B/C/C2
clutch pressure plate will fit 'all' RM250/370/400 up to '81
clutch inner hub will fit RM250 A/B/C/C2
clutch cover will fit RM250A/B/C/C2
engine cases can be used on RM250A/B/C/C2
right crank half will fit RM250B/C/C2
conrod, bearing, piston/rings (double ring) can be used in RM250A/B/C/C2
primary drive gear same as RM250A/B/C/C2
reed valve will fit all RM250/370/400 up to 1978
selector drum will fit all RM250/370/400 up to '78
selector forks suit RM250/A/B/C/C2
selector shaft (unwelded) fits RM125/250 A/B/C/C2
kickstart shaft suits RM250/A/B/C/C2
driveshaft suits all RM250 up to '81
2nd drive gear suits RM250 A/B/C/C2
2nd driven gear suits RM250A/B/C/C2