my version on mechanical brakes
 

seems if you get the leverage right any servo will work. i got an rc10gt reciever box and taped/bolted a hitec 125mg airplane thin wing servo on it. wala....

next to figure out is the radio. i have it mixed on channel 3 for now BUT turning down the expo on brake in the radio looses reverse. guess i should turn down brakes in the MM. also need to figure out how to wire my transponder that used to hang out on channel 3 for power....

works awsome though with just rear mechanical brake. with 30000 dif oil it stops good on the street. tap the brake entering a turn and the rear swings out like it should.
and now my reciever is out of the weather.:-)