When it was the AUF it was not mandatory to belong.
Fencehopper,
Wasn't then, ain't now -----
unless you want to go flying in an AUF/RAOz registered aircraft -------then it was mandatory and is now!!
That bit has not changed, where on earth did you ever get the idea that you could fly an AUF/RAOz aircraft (legally) without being a financial member, and having a suitable pilot certificate, ever??? ----- and the aircraft having the required volume of paperwork complete and current --- whether you own it or not!!
Unless you go back before the formation of AUF ---- and what some people were doing, all those years ago was never legally tested.
Tootle pip!!
PS: Funny thing , I recall (many, many, too many moons ago) the Tiger (as in DH 82A) I was flying was referred to as a "rag and tube" or "rag and string" machine, by all the untramegatrendoids flying their bright and shiny "spamcans", aka. Cessna C-1blah, blah, blah.
We preferred to think of our aeroplanes as real aeroplanes, and ourselves as real pilots --- DH never ran an ad campaign claiming flying their products was just like driving a motor car.