I would interpret race as the chassis that were intended for race cars, as they were slightly different to the normal cars and at one point they stayed with under dash handbrakes and round tunnels after the normal ones changed, but could be registered Track would be used to differentiate those cars that didn’t have the parts to fit things required to go on the road. Maybe no handbrake mount brackets, wiper mounts etc. Intended never to be road cars. The perhaps road comment on that just seems that whoever made the list up didn’t exactly know and guessed but unless you know who did I suppose we’ll never know