Jim
Welcome to the club/forum. My goodness you certainly had your share of XJ6s. Fifty One cars in sixteen years could possibly be classed as an obsession to Jaguars.
Good luck with your S-Type and keep the battery regularly and well charged, to avoid electrical and numerous warnings cropping up. I use a CTEK MS 7 with my S-Type and have it on charge at least once a week for at least 24 hours. I learnt by experience that it was the safest way of avoiding many false and misleading readings and warnings.
Best Wishes and Regards, John