Remember recently (ok a couple of years ago) seeing one identical but better condition in 'Union Jack' Livery featured on 'Chasing Classic Cars' TV Prog. IIRC the guy who runs the show (Wayne Carini) used it for a while and sold it on for c US$70000.
Edit: Found a link to that one at Bonhams in 2015....
https://www.bonhams.com/auctions/22717/lot/260/
Also a video of the truck with Jay Leno and Carini reviewing / driving it around LA.
https://www.youtube.com/watch?v=K88Nw_oyHVs