Bizarrely, I see that Rivarossi are now making a prototypically correct model of this but, of course, in HO (why, oh why didn't we go to HO gauge in the UK back in the 80s?): https://uk.rivarossi.com/products/rivarossi-h0-187-br-4-axle-tarpaulin-wagon-railfreight-metal-livery-period-iv-hr6495