Hi Steve, Yeah that tank was pretty grotty inside, good plan that you have swapped it out.
I think modern fuel doesn't help, the ethanol content promotes water absorption and condensation = rust.... I use a fuel stabiliser over the winter and will be filling the tank to the brim and adding stabiliser again this winter before putting it off the road. The stabiliser keeps the fuel fresh so there is little fear of ending up with a tank of rotten fuel.
Don't have the Leo's as yet, in the pipeline so to speak, might even be next year. I am in no rush, I like the standard alloys and they also suit the car.... Although I think the Leo's suit better

!
Be interested to hear how you get on with running around, its a nice car.....keeper ?
Definitely not a noob.....I still very much have that status...!!

Its a steep learning curve, I still have a lot to learn.
Cheers Dave