Welcome! First off let me say I do not own a Saloon. I have a 94 XJS 4.0.
First off, I’d like to offer a tip of the hat to fine folks who have given you some good advice. Not often a young man is interested in these old cars and since most of us are getting long in the tooth, we need to nurture the interest. Thanks folks!
I purchased a 76 Triumph TR6 in 1996. Not well cared for but it had good bones and no rust. Read a lot on line, which was not much back then! There were all kinds of upgrades developed over the years. My thought was to get the car back to a stock, original condition car. So I ignored the upgrade fever and returned the car to as close to original condition as possible to experience the car as designed. I was quite surprised after the systems were rehabbed. The car was very sporty and fun to drive.
My advice to you is work through each system and return it to original condition. Drive and enjoy the car for what it is. Then, once you know how it is supposed to be, you can consider upgrades.
Good luck!
Gordon