I have the standard white rubber strings on mine. The trick seems to be to tune it and then leave it to settle for a while.
The white ones cost around a fiver on Ebay, everything else is expensive in comparison.
https://www.ebay.co.uk/itm/274907004174?hash=item4001bbfd0e:g:ttQAAOSwOTRhGYci
Mesa Boogie M180 Power Amp Vintage 1982 120V US Tube Valve 600W
***THIS IS A USA MODEL 120V, PLEASE DO NOT BID IF YOU ARE NOT PREPARED TO USE A TRANSFORMER WITH IT FOR UK USE. I DO NOT HAVE A TRANSFORMER SO SUGGEST YOU BRING ONE ON COLLECTION IF YOU NEED TO TEST IT.***
I have a Squier Standard PJ - you can pick them up for around £150 - like B5 I was surprised how good a bass it is for such little money.
There are lots of basses for not much currently that deserve more recognition - this is one of them.
Question for the OP: Clearly not the original bridge and the replacement seems to have been move behind the original position - is the intonation right??
Hope that nobody from Uni of Herts is reading this post...they'll be offering degrees in gluing to go with the other bulllshit degrees they already offer.
Paul Kossoff's parents actually lived in Hatfield. However his dad, David Kossoff, died in 2005 so any hope of getting any info from the family is unlikely, to say the least.
I can spend that money many times over....