After comparing the quoted measurements of these buttons with my existing buttons, I found them practically identical. I purchased some to replace existing ones which had broken. I have now fitted some and find them A,OK. So much so that I am replacing all the old buttons with these new ones.
At a £1 each, thats less than half the price I`ve been quoted elsewhere.
(1953 Wheatstone Anglo 40 button). Cheers, Zak.