Hello Picture,
Welcome to the club. I can vouch for the series basses as likely the most reliable instruments around with the small caveat that you are buying a 40 year old instrument and it’s hard to know exactly how it has been treated in the past. Mine have been with me all over the world and never let me down. I have a 76 custom series, a 78 series 1, and an 79 series 2 fretless.
For reliability, firstly, the necks are rock solid. My long scale 76 series two custom can move ever so slightly from the depths of winter to scorching summer but my medium scale series one does not move, ever, unless you adjust the truss rods. Travelling internationally, I’ve always found my action the be mm perfect after each flight without adjustment.
Secondly, the pots in the basses which are another usual source of pain in other instruments, are several grades above anything I have in other basses. These are self cleaning and normally dead silent as they are rotated when plugged in.
In my experience the hum cancelling circuit has worked for me perfectly, without the famous upgrade, on stages in China, Australia and in Ecuador. It has never hummed under lights. I have heard that some others have had some noise due to mobile phones etc but haven’t experienced this myself.
In your position I would certainly purchase new 5 pin cables (at least 2) and check the voltages in the countries you are touring. You will need to use the power supply and the old ones are not voltage switchable. I have used the 110v one for years with a small 240v:110v travel transformer without any issues so this may also work for you. Alternatively investing in a new switchable voltage power supply may be a good option for you.
Batteries in the series basses only power one pickup, and last for about 20 hours of play. You need the power supply to unleash the full potential and you will almost certainly want to use one on stage for big gigs. Oh, and get a really wide strap, they are heavy.
I’m sorry to say you are most likely about to go through a transition where you won’t want to play your old favourite basses anymore. For me the series 1 was that much clearer and more articulate than my others that included PRS basses, Warwick, Pedulla, musicman etc. - it’s really hard to go back.
Post some shots of you on stage with your new bass: we like to see pictures around here.
Cheers, Garth