My turn ! My turn !
M and B May and Baker. I thought it was M&B 693 which if you goggle you will get some results including a series on the tmt of...pneumonia.
penicillin - my father was shown the Lancet paper in 1941 by - a German guard. He was in a POW camp and the problems over availability are well known (it wasnt) but would have been used in general practice by the late 1940s.
If it was a one off - your doctor might have got another GP in for a second opinion. Something like the first case of measles or polio would be widely discussed as the consequences were so dire. Making a diagnosis even if there is no effective treatment, you can see may still be important.
Fluids by mouth, kiddie aspirin, keep warm, fire in the bedroom might have been advised. When my sister got pneumonia at this very time, they did not admit to hospital on the excellent grounds that there was nothing more to be done. Oxygen therapy was experimental. Home oxygen not for another forty years. Drips in kids were unheard of, for another twenty years.
My brother remembers looking over the bars of the cot and seeing a blue child. Another member of the family may have come to help your mother nurse. After a few days, My parents employed someone in the village to come in and nurse at night - basically her function beside sitting by the bed with low light was to wake my parents and tell them the child was dead - actually she survived.
oh goodness those were the days !