Ian, i think what you are talking of is a dry monthly lease. Singh at Falcon air will do you that sort of deal at a similar price. You need to ask if, and i strongly suspect this will be the case, you are obliged to pay for x hours/month. Usually this will be 30-40 hours/month. Singh will let you have a 152 on 30hr contract, so you pay £1200/month, if you dont use all the hours a roll over agreement can usually be made. As for hangarage, why not park it on the grass? A 152 will live quite happily out doors and as it doesnt belong to you why incur the extra expense?
I would say the figures would probably work out something like this:-
1. Parking - £100 (including landings@ a small grass field)
2. fuel £900 (25ltrs/hr x 30hrs x £1.20)
3. Lease £1200.
4. Sundries £200 (Oil,Cleaning,etcetc)
So that comes out at £80/hr. Not bad considering you have control of the plane, but if your'e hit with a long down time, work commitments, bad weather, or other reasons, except for fuel the other charges will continue to acrue. Also tech issues, maintenance have to be discussed. On the other hand if you go to a club and propose some kind monthly account or other arrangement, then i think you would be able to get that rate or cheaper for sure.
Have a look at Full Sutton Flight Centre! C150@ £70/hr Wet and only £65/year membership! and they have two planes at that rate, one is even an aerobat!
Basically i would want two or three other pilots with an agreed financial commitment in place (Acompany bank account for example) before i whent down the route you are thinking of.
Whatever you do, have safe and fun flying!
PB.