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The NAMC’s “Catalog of all Series Matchbox Models” (second edition - thanks for the copy, Dick! ) has 53-3A listed as having a blue interior. Houghton also has an unlisted model heading his listing as variation 53c-1, this time as Nick's code 1 but with a dark grey interior. I would suggest that both these models are pre-productions/interior colour tials, and analogous to the well-known violet-interiored version.
The AIM “1-75 Series Regular Wheels” catalogue (second printing, 1983) has no variations not already covered by Nick, and neither does Stannard.
U.K. Matchbox did not cover the model.

You are very welcome Idris. Thank You for continuing this series of Guide comparisons. We are learning a little about known history of our regular wheel series from these different Guides that many of us have forgotten till now. Others can now learn for themselves what details may have been lost for 40+ years and then highlighted on our Forum for discussion and documentation today.
I am sure you are correct on these varied 53C early interior colour trials that I am sure are still on the shelves in some private collections around the world. Are they perhaps interesting enough to list these known colors as possible trials in Nick's Guide as a sub-note?
Merry Christmas my friend! kwakers