Please keep the final build standard with the 105mm gun, as it represents the final development of the A24, A27 Cruiser tank series. Yes there is always the temptation to make it a Cromwell, but 00SP36 is unique and should be preserved as such. In 1943 the tank designers said that you could not fit a big 17 pounder gun into a Cromwell, so embarked on Challenger A30 and then Centurion. But they were wrong, as Charioteer showed.
When I worked on the tank the suspensions were in good order and shockers held their oil, so there should be no need to strip off the side armour. The suspension greasing/oiling needed to be arranged, but that is fiddly but simple. If in doubt fit piped grease nipples to improve nipple access. Make sure the correct oils are used - the gearbox was filled with OC600 and the hydraulics OM13. I suggest that you do not initially need power traverse, a Tiny Tim or a working generator. The vehicle batteries are only used for starting, after which I turned off the master switch to preserve them. The Meteor 4 I fitted started OK without the need for the booster coil. Make sure both the magstop circuits are working. Make suree the coolant has some antifreeze in it to stop disimilar metal corrosion. You might want to run it without a thermostat, as they can cause a lot of damage if they jam shut. Watch out for asbestos in the exhaust shields and exhaust pipe padding, where the pipes go over the fan assembly - I would fit non-asbestos pads. If there is no petrol tank close to the manifold, then do not fit the asbestos heat shield that side. One possible problem was with the track as the circlips were very rusty. Inside the circlips were grooved spacers which get lost if the circlip fails. You need to fit new circlips and make sure the spacers are fitted - you may need to make some more on a lathe. As with any Cromwell you need to give the driver a good set of mirrors. The driver's vision porthole also has a sliding internal perspex window which needs to be in good condition if you want to drive on grass or in dusty conditions. I checked all the wheels for rimrock, tightened a few wheel bearings, but that will need doing again after this amount of time. The track tension adjusters were seized, but doubtless will move once "persuaded"! If the engine is out then I would fit new hydraulic pipes throughout for the cluch, brakes and steering systems.
John