Michael, I see what you mean by "nonsense" chassis plates.
In 1961 Angus Hyslop raced a Cooper Climax T45 2 litre chassis F2-13-53
In 1962 - 63 Hyslop raced a Cooper Climax T53 2.5 litre but surprise surprise it had the same chassis number F2-13-58
This latter was the car bought by Palmer.