Hudswell Clarke 20 and 21 inch gauge steam-outline locos - scale?

[009 micro modeller]

I’m thinking of the locos in this article, as used at Blackpool Pleasure Beach and the North Bay Railway in Scarborough: https://www.tapatalk.com/groups/mrw_forums/larger-than-life-t1659.html

 

Does anyone know whether these are roughly ‘scale’ in outline, and if so what scale? At the moment I’ve got plenty to get on with in 009, plus a few side projects, but was looking at some photos of the Hornby TT stock earlier and idly wondered if it would work as a vague representation of this type of 20 or 21 inch gauge line in 7mm scale. The other one that would work (from a gauge point of view, again I’m unsure about the proportions of the locos) is 16.5mm gauge in 1:32 scale; this would be a different calculation as in 4mm, 00 gauge track is narrower than scale.

 

I’m aware that, for instance, RHDR 15 inch gauge locos have a slightly weird scale/gauge relationship, effectively being 1/3 scale but on track roughly 1/4 of standard gauge (it has been previously suggested that Triang TT3 stock could roughly represent them in about 1:32 scale), but I’m not sure if the wider-gauged Hudswell Clarke steam outline stock has this issue. Visually I find the North Bay locos quite well proportioned, and aesthetically they still seem to be the best looking steam-outline diesel locos around.

[BernardTPM]

They are roughly 1/3rd scale, though the Butlin's Princess Royals are closer to 'scale' than the LNER A1 types where the cab is too long.