Highlandman2

I have had the good fortune to obtain 4 frets of DS 12-D1-7, wagon chassis. The wheelbase is 56mm which is 8ft in 7mm, solebar length is 88mm 12ft 7in approx. Can anyone tell me what wagon these frets represent and is anyone able to direct me to a set of assembly instructions please. Looking to use these as the training project for assembling soldered construction kits, especially as they were so inexpensive - £1.25 each. many thanks Highlandman2