As James Dunnett well knows, I have made no claims to have detailed knowledge of any of Erno Goldfinger's buildings apart from Albemarle Street, but that I know intimately, having worked on the design under Erno's close supervision from the initial sketches to the final production drawings.
Until the incident I described in the letter published on 5 December 1990, there was no hint of the use of a proportional system of any kind, and by that time the dimensions had been finalised.
There is a very minor difference between the 1/8' scale elevations in the riba Drawings Collection (Drg. no AS/34 - the one on which the notorious diagonal lines have been marked) and the building as built, to which I referred in my letter (aj 11.4.96): the original width of the stone facing slabs was 1'0', but this was increased to 1'2' to improve the detailing of the window frames.
I suggest that, whatever 'evidence' Dunnett may have for Erno's other designs (which I am in no position to refute), he has none for Albemarle Street.