We know that T53 'F2-13-58' is nonsense - Angus Hyslop took a car carrying that chassis plate to the UK and returned with a T53 that, for reasons of convenience, retained that plate.

A T53 could hardly have been built in 1958 - however Vercoe's book refers to the car having been 'low-lined' by Cooper...not the work of a moment. David McKinney was the most fastidious chassis number noter I have ever encountered. If the 'T55' wasn't 'F1-2-61', then I'd be amazed if he hadn't noticed it.

I am catching up with Jim in a few days - I'll ask him what he can recall.