Hi, Frederick. I don't know whether you have managed to get any other information yet, but I have now found the sales leaflet I have, which relates to the 1987 range of Trophy caravans. I don't know what age yours is, because the Silver range (model names with an Ag prefic - Aglia, Agilic, Agistar and Agrarian) were in production for several years before that. Later models had a brownish exterior trim, older ones had blueish decals, which may help.
1n 1987, no Agrarian 6 is listed, only the 4/6 (which we had) and the Agrarian 4 De-Luxw, which I think was a twin axle. The unladen weight of the former is given as 15.39cwt, MGW 21.60cwt, and for the latter as 18.34cwt and 23.57cwt.
The manufacturers address at that time was Trophy Caravans Ltd, Orchard Mill, Westhead Road, Croston, Nr Preston. I know that they moved to another address, still in the Preston area, before ceasing production, but I'm afraid I don't have that.
The chassis was not the standard Al-Ko chassis, but was made by another company, which I seem to recall was called something like 'Ashfield Developments'.
We later had another Trophy, a 1991 Olympic Silver, and were well pleased with both the caravans. Decent construction, fairly lightweight, good level of equipment (for the time) and excellent value for money.