Andy Evans wrote:

Its no wonder the ECC40 is plentiful and cheap, the makers made a mistake to
use a pinout so different to the status quo
of octal, 9&7 minis.

But what was the status quo at the time it was made? It's an old valve.

I checked the Radio vademencum and rimlock tubes were introduced
somewhere around 1948. The 9pin Noval tubes are found in radios from
about 1951/1952.

Corné