Cliff Hill quarries of markfield near leicester bought a lot of these around 1958 short wheelbase 4 wheelers like the previous writer said cheap only lasted a few years some ambitious operators in the leicestershire area converted them to 6 wheelers usually with disasterous results.Thames trader was a better bet in the lower weight range NCB used them widely for residential coal lorries…moving vans also had trader chassis…the only tipper operator I remember having lots of these was tarmac roadstone at their corby northants depot.