Thanks folks...
Archard - I believe that it's a C172N.
So far I've only talked to the group 'spokesperson' on the 'phone so I don't have all the answers. But I understand that the group is a mix of retired and working people, some of whom prefer to fly during the week and some of whom prefer weekends.
Sometimes group members do take the a/c away for days or weekends but I need to find out exactly what the rules are for bookings and so on. I gather that members have been known to take trips abroad, so I guess as long as everyone plays by the rules and doesn't abuse their entitlement, everyone can get their fair share of useage. On the other hand, there's no point in my buying a share if I can only use it at inconvenient times.
Obvious advantages of a larger number of group members (aside from reduced initial outlay) is increased utilisation, which brings down the running costs per hour. Apparently the engine had a complete overhaul recently although I'm not sure when the CofA is due - I shall ask - and is about to have it's first 50hr check since the overhaul.
Oh, and I forgot to mention that it has a Garmin GPS (90? - not sure) no-map display type - but apparently this is about to be replaced with a colour moving map display GPS.
The monthly costs include hangarage and insurance plus a proportion of the hourly rate to build up the maintenance fund, but I'd like to see the books to see how much 'rainy day' money is set aside already and how much of the £55/hr goes into it. No landing fees at home base either, which is a bonus (but probably quite common I'd guess?).
The group members include an instructor, who can do the conversion training/revalidations/renewals. The spokesperson implied that the instructor does this for free, but I'd like to speak to him her/her personally and find out if they are truly so generous!
Clearly I will need to ask many questions and get to know the people in the group, as well as the a/c....