Was the H1 style of safety valve shown in both pictures patented and if so, did it have a specific name? Without this particular piece of information it would make a search in say, Alan Gibson's list or Wizard models a protracted and very tedious business.
Also, for another project I would like to locate some 4mm scale Salter safety valves (the kind fitted to all the Terrier domes). Lastly, I'm looking for a source for a flat circular plinth-like base on which sits a small single safety valve/whistle, as on some early Billinton E series tanks and Stroudley's 'West Brighton' tank. Actually it's been sitting under my nose all the time: EB models has a page on the E3 radial and they make a model of it complete with Salter safety valves and that single whistle sitting on its little plinth. I found two photos of the class both in Stroudley Goods green, one of them shows a spanking new, just outshopped Watersfield no. 457, probably photographed at Brighton. That photo's too big to load here, but the one below of Storrington will do, though the engine's starting to look a bit grimey.
vince