Thanks for that info. I've got hold of the number of a local auto locksmith who is supposed to be able to sort out keys.
Thanks for the eBay link. Having searched eBay further I've now found a complete blank key with transponder and the remote buttons for £39.99.
I'll chase my indie who should have sorted it for me ages ago, but can't supposedly get hold of ready keys or blanks. I'll try the locksmith and see what they can do (and for how much), but may well go for the blank I found on eBay and get it cut and then programmed to the car.