Fred, I was very impressed with your e-book on the locomotives from Aster. But I was disappointed that you apparently did not have the opportunity to get to know and report on the late US-sponsored Aster models. The Berkshire brought Aster back to properly researched and detailed US models after a long drought filled only by the non-specific Mikado. The S2 followed and offered increased detail, a free steaming boiler, drain cocks, a whistle (admitedly not Aster's strongest suit) and a first for Aster: a Vanderbilt tender. The Challenger, despite quality control issues at the factory, brought this increased level of detail to articulateds and even had draincocks - on an articulated. All this was presented at a price considerably lower than the last US articulated that preceded it - the Allegheny. The FEF was the final US commissioned model and was a model with the high degree of detail that Aster buyers had come to expect from the US commissioned models. The boiler was extremely efficient, so much so that the locomotive would maintain pressure at speed even with the draincocks open.
I expect that I have not done these later US models full justice either, but I wanted to make sure that they were not glossed over in an otherwise outstanding book.