Rhymney "A" class livery detail

[NeilB]

I'm in process of painting a 7mm scale model of a Rhymney "A" class radial tank and would like to have confirmation of the colour in which the wheel centres and spokes were painted when the engines were new. I may have missed something very obvious, but I can't find a reference to this in either the Circle's book of Rhymney drawings or in the relevant volume of Nigel Digby's books on liveries. The drawing of the class in the Circle book shows lining, but no details of livery below the running plate and no photos of engines in service in pre-grouping days.

My working assumption is that the wheel centres and spokes were engine green, but I'd welcome some information before I start wielding the paintbrush!

With thanks,

Neil Burgess