Maybe try the Black Beauties. It is what he uses now. They sound like a subdued round wound.Jumping in – did Geezer use flats, and if so which ones do you recommend to approximate his tone? I'm looking to put some on my P bass and I've never used them.
Or any hexcore nickle with the tone rolled off and playing just below the neck.
To be fair, there isn't really a single Geezer tone. After the first two albums, he has been all over the place tonally.