I can only assume that as you are an experienced builder that you have a copy of the above mentioned book, if not I would recommend that you get one.
I have made a few boiler of different types and sizes all to the spec's suggested in both K.N.H. and Martin Evans books. Most of the removable fittings have been made from brass, I make most fittings but always assumed the ones bought were also made from brass, apparently not?
I think I will continue to use brass until I know bronze and monometal become mandatory.
I don't think that any other metal other than brass will be made mandatory for fittings.
Over the years that I have been making boilers and fittings there has never been any other metal with the sections that can be had with brass, for instance Phos bronze and Monel are not available in the Hex range that can be had in brass, plus the cost would be prohibitive if they were available and I don't know of a supplier who makes fittings other than in brass.
Like you I make all of my own fittings from brass and will continue to do so.
Speaking only for myself - - - - please offer your results in written form with pictures.Mr Tony Bird,
I have been meaning to make various gauge glasses for a few of my locos / projects I am working on, and had been putting them off for a while. Finding decent and accurate drawings or details was quite tricky. I had dome some drawings myself, but not taken the plunge to actually fabricate any as yet. Your post has spurred me on, and I will try and do some this weekend! So thank you.
I will be videoing my progress and will post a video in the near future. (Depending on how successful I am! ha)