Purely a guess, but I think that these skips may be the new ones from Slaters Plasticard, not O-16.5 but to 1/32nd scale. They are a revamped version of those originally produced by Bantock and Lantz about 5 years ago and are pretty accurate models of a Hudson Rugga Skip. I say pretty accurate, as the gauge is slightly out with the 16.5mm gauge version, the 3/4" gauge version is pretty much spot on. As it was Hudson's practice to produce the Rugga proportionate to the track gauge, they should in theory be right for Gn15, but some of the details will be a bit small.
They are available direct from Slaters
or from Branchlines (firstname.lastname@example.org
) or tel 01392 437755.
It should be noted though, that these are smaller than a Gnomy Skip, I checked the two side by side at ExpoNG.