Now it's cleaned up and working you'll probably get your money back.
Looking at the bridge, it's quite possible that it requires a medium-scale string even though the playing length is short scale. If you're going to buy new strings you need to make sure you get the right speaking length, this page explains it a lot better than I could, with pictures even - https://www.stringsdirect.co.uk/blog/how-to-measure-bass-scale-length/
I think you're a bit harsh on Chris Squire, I'm not sure he belongs in a metal dustbin. Besides which, you'd have to take Adam Clayton out first.