Playing open strings is good. It's four notes that are available in any position.
Especially on a fretless where it's four notes that are always available and also in tune.
(Obviously more notes on a fiver, etc.)
Me too but also Mamas and Papas, Turtles, The Assocation, Fifth Dimension, etc, in fact many West Coast/Los Angeles session players. Although some e.g. Carol Kaye were using a Precision.
Fender Jazz with flats (preferably GHS Precision Flats in my view) and played with a heavy pick over the neck pickup is a 1960s thing and not just TV themes.
If it's just a couple of bases in cases, for a few months, I'd ask musician friends to look after them for me ... they usually don't mind too much having an extra instrument lying aound.
The last time I auditioned for an 'originals' band, I was sent mp3s of the songs along with chord sheets.
The time before that there was nothing and no clues beyond 'it goes like this'.
You won't get private market value selling equipment to a music shop and neither should you. They have costs (inc VAT).
If the bass (or whatever) is worth so much more, in your opinion, then sell it privately.
I'd reckon most people wouldn't know Macca was a bassist. They'd call him a singer/musician/Beatle/composer/Liverpudlian before they'd say bass player.
The Rickenbacker is not iconic of the whole Beatles thing in the way that the Hofner is.
The violin bass image stands for The Beatles as a whole