The legislation trusty220 refers to is the Road Traffic Act which was revised/amended to encompass more than what we generally consider to be roads. This is when rally fields and showgrounds amongst other places became ‘Public Places’ and only affects ride on machines such as garden tractors and ride on lawn mowers, it does not include pedestrian operated machines with a trailer or riding bogey eg a Trusty or British Anzani Iron Horse. Various insurance companies can provide the necessary insurance for shows. The machine does not need to be taxed or registered, it does need some means of unique identifier eg serial number.
On a general note, please refer to the BAVCC Safety Code, a copy of which all members should have received with the April 2022 issue of The Cultivator.