JB4 tune means it's been thrashed, the owner didn't do a mod like that do nana it around.
These are pretty common so you could likely find a completely stock one, I'd find that if I was in the market for such.
The first rego shows a odometer decrease too, 10,046 down to 4,299km, suspect yes, but It might be as simple as the kms being entered wrong, instead of 1,046km some wof plonker wrote 10,046...