I have a load of these Mini Z bits n bobs, the chassis you have is one of the first that was released by Kyosho and at the time
loads of hop up parts were available for them.
This is my race tuned chassis, oil filled damper, tuned motor, tuned springs and carbon damper plates. you could get the small RX antenna ( before the days of 2.4 radios ), ball diff and a load of
alloy parts to add. I have the lighting kit for some of the rally body shells which is what the red plug is for on the top of the chassis. Tones of fun to be had with these
little cars. I think parts for these are now really hard to get hold of, I've not used mine in anger for about 15 years now. I must have 8 or 9 body shells , two chassis
and a boat load of hop ups. I might be willing to part with them if you are interested.
I still have all the Kyosho instructions for the cars and the hop ups if that's any help.
The more standard chassis that I have, this is vey close to the base stock supplied kit.
And the TX and car carry case
They are really good fun and you can get some great performance from them with the right bits.
Regards
Dan