You should try the following:
1. Call MRC and see if they have any parts that still work for this vehicle
2. Check Sheldon Hobbies (www.sheldonhobbies.com
) and see if they still carry any of the vehicles as I believe they still have some old stock to move. If they actually have some kits in stock may be worth buying 1 or two if you really want to get this running.
IMHO, you will be hard pressed to fine parts specific to the vehicle. May be better to opt for a Stampede or some modified stadium truck ( T3 with monster tires, very nice and cheap ) so you can find some parts for anyone else interested in doing this as well.
The vehicle itself was a tank back in the day from those who I know who had it.