Morris Minor Owners Club

It struck me the other day whilst I was researching my own car’s history that the model numbers of the minor don’t make sense. We have the mark 3 that was produced up to October (ish) 1963 and then into its last incarnation of the mark 5, the minor 1000.
But what happened to the mark 4? Did it not get past development or was it abandoned totally in favour of the minor 1000.

I have read the bible (rays book) on it and I cannot really see why (or I’ve forgotten it was in there)

The Series 4 chassis number prefix (I assume that is what you are meaning?) was already in use in production of the Mini, so the Minor 1000 had to be given the series 5 prefix.

I've seen the statement "NOTE: Series IV was allocated to the Mini-Minor" on a couple of lists of Minor notable the Potteries website, and it took me ages to understand what had gone on.....
Their numbering prefix system crossed Models without any 'logic' to the outside person when it was changed in 1958

The 4 had been allocated to the Morris Mini MkI, because the Chassis prefix for a Mini MkII when it arrived in '67 was M-AS26, as
M = Morris
A = A series Engine
2S - 2dr saloon
6 = Series 6

Absolutely barking mad

It is simply a manufacturers code system and very easy to understand - once you know - I've always thought.
Most car makers have similar identification codes which are used and understood by them and their dealers, partsmen etc.
I have never heard of anybody referring to a Morris Minor as a "Mk3 or Mk5" in any case and they were not marketed as such

Yet the 2 previous iterations of the ID prefix, did identify as 'Morris Minor', either by the use of SMM on the early MM cars, or F on the 52-58 style plate, covering MM, SII and early S3....
But I totally agree the Minor has always been the MM, SII or 1000; the use of S3 or S5 on the 1000 is a bit superfluous, considering the number of different change points for alterations.
It's not as if they actually had the Indicators, Wipers and Facia and Key Start all coordinated with the change of Engine.....