Hi John
We concur with all the other comments, and good to know that this particular XJS is going to be cossetted.
We'll also concur with regard to the Carcoon....an excellent purchase and you will be well rewarded. Our 6600 mile '07 XK lives in one. We have, like you, a dry and secure (large sized) garage at the end of our rear garden, but when we first purchased the XK (in April '16) we found that although the XK remained dry (apart from an occasional condensation drip from the roof), it did get dusty. A (not cheap) car cover was purchased but this produced more condensation than enough and was rapidly returned. Enter the Carcoon (in our case, a drive-in version i.e. a strong free-standing metal frame with the cocoon attached over it) and the XK now comes out of the Carcoon in exactly the same condition as it went in. You will, of course, find that even if the car is put in slightly damp, the fans and vents will dry the car off. Of course, the Carcoon is not particularly cheap, but then how many hours of professional paintwork etc would you get for the cost of the Carcoon?! Not many!
Have a great time with the XJS, and good to see it with an original Glamorgan issued number plate (last two digits 'TG').
As always, happy growling