Nice one Dave.
FWIW, In the VMX issue that featured Steven Gall, there is a Dirt Track race pic showing a slider-framed Kaw that looks like a KX 125-based machine. Bike # 74 on the outside, which I think is one of the Brisk Sales bikes - possibly Tom Gibson the pilot. It looks to have the carb cover removed & replaced by something larger, no doubt to accomodate a bigger carb