Rickenbacker also made contoured 4003 basses known as the 4003S. No trianlge inlays on the fingerboard but they I love mine.
If you have to have the triangle inlays, you might can find a 4003 that someone modified the body by removing the binding and creating a 4003S body on a 4003.
I have one that I'm not selling, btw.
What a lot of people are missing is that in the 4001 models, people didn't know how to do proper adjustments on them and they invariably broke them or left them out of adjustment, thus making some seem worse than others.
What also doesn't help is that in their history, both 4001 and 4003 have had alternating eras of thick necks and thin necks. Even to a knowledgable person, it's difficult to keep track of which years had thinner necks and which had thicker necks.
There's also the notion that something magical comes from these basses. And because they aren't seen in every store, when they are seen everyone wants to play it. Invariably, someone won't like things about it.
There's nothing anyone can do about that.
My first contact with even seeing a Rickenbacker was seeing one in a store in the 80s. That bass didn't give me a preconception and ended up going home with me. I regret selling it several years later but I'm back in the fold.
To some, a Rickenbacker just feels like home. To others, a Rickebacker just feels like ass. There's nothing that can be done about that.