I used to own a 1947 German upright that was used as a rental bass for much of its life, I can't remember the brand but it was a replica of a 1700's Viennese build!! I sold it when I was laid off about 7 years ago regretfully to pay rent etc... I don't know if it was imbued with players mojo over the years, but I will say it had a nice broken in feel , no need to sand the back of the neck as finish was naturally worn, I would play it sometimes for 6 hours a day, to the point of my hands/arms were exhausted!!
I never should've sold it, but it did go back to the store I bought it from, presumably to be rented out again so hopefully others will love it too! I currently own a 1981 Tijuana made mockingbird bass, it has alot of nicks, paint chips, electronics need fixing, the frets are almost gone, it was well loved and played before i ever owned it, also the most comfy bass I've ever played and it was the best sounding until the electronic noise started happening, to me this all qualifies as "mojo"!!
As hippy/dippy as it sounds, i do believe instruments can retain energy from owners if they were well loved and played, but i don't think it'll make you play better but instead inspire/motivate one moreso than a fresh out of box bass, but of course this is just my opinion....
awesome fender collection OP!!!!
edit: I have yet to play an upright as good as that one, really, really regret letting it go