That CT truck sure looks the part. Aside from the internal roll cage and mounted rack, the Hella lights look correct. They are "rimless" fog/flood on the inside, and spot on the outside. The CT Adventure Wear and LR logo stickers on top of the windshield are pretty well sun faded. The only thing I can make out on the piece of paper behind the wipers is "It's Real".
The LR sticker under the gas flap and door stickers are too new. However, the main thing that sticks out to me as missing is the lack of team names, or remnants of them, on the wing in front of the flag. The wheels also look to be the 3 spoke RR type, not the steelies seen on the trucks on event.
It's obviously not from 1990. That was the intro year for the Discovery and a 3 door model was used in the Siberia CT.
It's probably not from 1991, as that was the last year of the blue colored CT logo. Of course the roof rack plaque could have been swapped from another evented truck.
Along those lines, probably not from 1992 Guyana either, as that year they went to the original black text for the CT logo, originally used from 1980-1985.
We know about the 1993 truck.
We know about the 1996 truck.
So that leaves either 1994 Argentina-Paraguay-Chile or 1995 Mundo Maya.
The 1997 and 1998 trucks had the blue and pink graphics along the bottom of the doors, and very large country flag stickers on the cargo side windows. Well, also, the 1998 Mongolia event used the Freelanders and 110 support trucks. There were no Discos for the final year.
Any chance you have some other pics or info from that show?
edit: Also just realized there are no convoy plates on the hood, or even holes where one would have been riveted to the hood. The convoy plates were used from 1995-1998.
edit 2: British By The Sea 2014, jump to 1:41 and you'll see it in the upper right with a few other Landies.
[video]vhttp://vimeo.com/97779294[/video]