It appears to be in neither the LOK book nor the LGB Compendium, and I would assume it was almost certainly an "uncatalogued" item. The only one I've seen was in Great Eastern Models in Norwich, back in the days when they had a large upstairs room of mainly LGB - it would have been about 2003, though they may have had the set in stock for a considerable time by then. They were splitting the set up and selling the models individually, and I bought the blue Matra crane car from them for a very reasonable figure (about 35 quid if I recall correctly).
So, all I can really tell you is that I know it is a pre-2003 release!
Jon.