I've got the top 6 feet of a crashed Lightning (XP707 'DB') on my desk behind my monitors. It's light enough to sit on the desk, I can easily pick it up, but there's not much room to the ceiling. It looks great, but it's not polished and shiny like those Motoart pieces. It's leaning against the wall, so probably sits 10-12 inches out from the wall. If I had more time/motivation I might put it actually on a wall rather than just sit it on the desk.
Before I got it I nearly got a complete one, but it would have only just fitted in my extension, was way too tall for a normal height room, and WAY to heavy to move (300kg+, if I remember right). I think it had large milled sections for mounting on the fuselage, which the fin tip doesn't have.
Personally I think a complete Jag tailfin would be too big and heavy for a desk in a home. (although I'd like a home big enough for that as decoration).
I'm struggling to find an easy way to post a picture of it, but if you PM me I can email you something to show you what it looks like in place.
Phil