Are you saying this isn’t genuine?
I mean it would be easy to buy a set of stacked knobs and swap them, and sell it for £10k more than this sold for if people wanted to exploit a market, but this is real, and rarer than a stack knob, but cheaper because many people paying £20k+ want a stack knob.
There’s literally tons of examples of 3-knob ‘61’s out there (AB has sold 2 examples in the past 3 months, both shown in this thread alone, a burst and a blonde) and no ‘62 stack knobs have ever been seen, obviously and for good reason. But hey, you’re the expert.
https://www.andybaxterbass.com/collections/fender-jazz-bass/products/1961-fender-jazz-bass-sunburst?