Stamps in the service book is a consideration, personally my car is old now so it dosn't concern me, I do all my own servicing and only present my vehicles for annual MOT's. The Zed Sheds around the country run by enthusiasts tend to hang out on zroadster.org, there is a zed shed HQ thread on there but a couple of more sheds dotted around the country, mine is in South Wales where a few of us get together to do jobs on our cars, usually a donation to the tools fund covers anything we do, pays for the electric etc. We just turn up with the consumables and get stuck in. We do have a no liability policy in force to which we all agree. Tends to be in my garage as I have a car ramp.