Your answer is correct and very comprehensive, yes, it is the Miles M2D Hawk.
My source is Brown, D. L. (1970). Miles aircraft since 1925. London: Putnam.
The story of the Miles aircraft company is very romantic and I like the light aircraft of the pre-war period. This one is particularly interesting as a three-seater. I am very happy that someone else is reading about the same topic quite by chance.
And yes, I know there were only five (your source mentions six?) made in total
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