Great job rebulding the car! Like previosulsy stated that is an original RC12L car. I believe it is a graphite version. In those days you could choose between a fiberglass and a graphite version. What is also unique about your car is the fact that it has the 2 hole front a-arms! This would make it an older version. Assocaited made a running change shortly after towards the 3 hole a -arm.
I would not do anything to modernize the car. Try and find an orginal axle and also try and find some 2 bolt rims and tires for it! If you really want to keep it vinatge look for a TOJ body and you would be set with a very cool collecter that might be worth a good "chunk of change" if you put it on E bay!
You would be very surprized at how much a guy like me would pay for it!