I picked up a selection of Roco HO European wagons at the Derby exhibition yesterday, one of which might be of interest to UK modellers as it's currently being advertised by Howes of Oxford. Pictured is the twin Cargowaggon concerned, positioned between two Bachmann VGAs for comparison purposes.
Although these things aren't correct for a 4mm UK layout I know many modellers do find them better than nothing at all. For what it's worth, my excuse is they're to go with some of my European stock...