You didn't specify what year that you have but most parts manual will have them listed for your particular year.
It's a 1957 with hydraulic rear end. I do have one manual and one part listing but neither have any info on those grease fittings (diameter/tpi).
Harley-Davidson was particularly fond of using 5/16x32 threaded grease fittings. A non standard size.
I'll start from buying those 5/16x32 grease fittings and see if they fit. Just getting used to unc and unf so never even heard of those unef. I'm only familiar with metric system.
From your post I get the impression you are not in America. Where are you?
I'm in Finland so your hunch was correct.
Thanks for replies. I'll post results later.