I still have three TRX1's and race one of them occasionally at our clubs Vintage series. A fine buggy still. Make sure you have the optional metal layshaft gear and the metal U/J gearbox outdrives though if your running any serious torque through that gearbox. I also added a beefier front bulkhead brace and a hingepin brace also, with lead inbetween the L & R front bulkheads and some more up front. I used Ballistic Buggy Losi 5-spoke wheels, with the rears slightly modified to take the axel nut inside the wheel rim and keep the right width.
For set-ups, luckily Craig Harris runs at my club so i just copied his
He used to run the TRX1's and 3's back in the early 90's and is here on o0ple, so if your very lucky he might see this and help you out... And Stu Wood was another famous TRX driver and i believe he's still on here too.