I have a few ideas for reducing the scare factor - well as much as I can given my arse will be on top of the front wheelarch and in road use it's RWD...
The tyres on it are older than me, made in Romania by 'Danubiana' - I googled this brand and found out that even when new they were dangerous.
There was never any chance of them staying on anyway! There are a few tyre options around the right size, including the BF Goodrich A/T which I've used on a couple of old Discos in the last few years, albeit in a smaller size, and they've behaved pretty well. No point going for noisy Mud Terrains or anything - I've never got stuck on ATs with good tread.
The other thing to soften the ride somewhat is to look at removing some leaf springs, and fitting some supplementary air springs - it can self-level then and hopefully provide a nicer ride. Handy if the eventual camper plans come off too, as it can level the body up very easily.
Some people have suggested PAS helps a lot - so in time I may look at the Corsa electric PAS system, but initially it'll just be a new steering damper and everything properly adjusted.