In Australia as long as the car is old enough and you are a member of an affiliated club you can get Historic registration for about 10% of normal registration but it is limited to using the car 60 days a year, club events don't count so you can attend a club function/trip and not use up one of your 60 days. I feel that is why I find people with about 3 MG's all on club registration. It could also be that there is always a chance of a 50 year old car breaking and they like to have multiple cars so they always have something to drive to a club event rather than turn up in a daily driver type of car.
Dave, I know what you mean about knowing every nut and bolt, I used to be able to crawl under my Honda S600 and remove most bolts needed to remove the engine without looking.