By popular demand?
Not a good thing for them to do, Jim. Painting across their shells reduces the shell surface area (by filling in all the pits and pores) and drastically affects their ability to absorb heat and ultraviolet from the sun. Heat (obviously) affects their mtabolism, feeding and digestion; UV enables them to change the calcium in their diet into healthy bones and shell. Painting across the scales of a growing tortoise will stop shell-growth too. Likewise, "cleaning" the shell with oil!
In cross-section the shell isn't smooth, it's corrugated. If you were to hypothetically "iron" it out, it would be about 50% larger surface area from what you normally think you "see".
I think 2/6d is probably about right. I wouldn't know, my dad bought ours when I was about 6. I remember it fell through our coal-hole into the cellar and I was absolutely blackened after I went down to rescue it. (Anybody else remember the weekly(?) coal deliveries?
) I remember rescuing hedgehogs from down there, too.
If regularly allowed to hibernate, mediterranean tortoises can live over 150 years. I think "Lonesome George" on the Galapagos is in his late 200's now? I think he's still alive?
About 10 years ago, I had a customer who used to board her tortoise with me when she went into hospital. She was in her 90's and told me she got the tortoise from a market stall in 1910. It was a wild-caught adult at that point, which would have made it at least 100 years old. Still had a strong libido for its age. It would try and mate with anything vaguely tortoise-shaped in its cage, water bowl, rocks etc.