Hi Howard, welcome
We compete in a lot of RTV's, there is no requirement for a return spring, most of us dont have one.
As for other bits, RTV is for road going vehicle so all I would suggest is good tyres and some confidence.
Scrutineering happens before any event and it's mainly safety checks that are carried out, seat belts, steering and load secured in the rear.
If your not sure then just come and spectate on the first one a see how it goes from there. Next one is on the 22 March.
Hope this helps.
Stephen