Regarding fob and key, check on eBay for a replacement set up ( BCU , Ecu, fobs, keys and barrel ) if you have a facelift. I replaced mine a couple of years ago when the BCU died and was fried lol. I purchased a Ecu,BCU 2 fobs and barrel with keys for £70 then just swapped everything over which took 20 mins. I then purchased another complete setup wit 2 fobs for £20 which I tested on my ZS and is now sitting in my cupboard.
As mentioned if you have pre facelift car with square 2 button fob then a second hand fob can be found easily in breakers or eBay and programming is cheap but you need the car with you for this.
As for the clock I would replace it with a Lucas clock from an early model 25,45 or ZR,ZS or rover 200/ 400. I had same fault on my pektron clock, repaired it then it failed in some very cold weather, changed a few pektron which all failed until I put a Lucas clock in few years back no more problems.
Hopefully you get it sorted before you go back, Bren.