Got a 1940's HD?, they got parts
Which was a major factor in my switch to HD almost 25 year ago. At the time I had a Suzuki GS1000GL (shaft drive). It was a great bike, low maintenance, almost as low maintenance as my Harleys, almost as easy to work on as my Harley's. The bike was only 10 years old. Everytie I needed a part for it the dealer woul have to order it, for oil and air filters to speedo cables and brake pads.
I've never had any problems getting maintenance items for either of the Harleys I've owned.
It's not as bad as it used to be but the aftermarket support simply doesn't exist for 25-30+ year old UJMs the way it does for HD.