yes i think the s/arm is RM125, possibly '79. Had a shorter arm in [thinking back], well this one seems a bit too long. The old use what ya have trick. KDX front wheel & a Chinese scooter cable altered for front brake & throttle. I got a 'free' bundle of assorted cables [scooter type] & a good starting point for making one. Have an old fashioned cable oiler you seal the cable into, fill with oil & pressurise it, works great & the chinese cables are made 'dry' but made well i recon. Gota go.