I will just add my 10P worth, as I have been a Geezer Fan for many years!
I am sure Geezer said he used his precisions up to Master and this record (in his opinion) has his favourite tone of Sabbath's 70s albums. The Dan Armstrong was used on Vol 4 and Geezer reckons that this album has his worst sound. He did however stick with shorter scale basses thereafter, 1st the White JB, (Sabbath Bloody Sabbath era) and then a succesion of JB SG ish styles sun burst maple neck also an 8 string (Sabotage era) then all black for (Technical era Gypsy & Its alright Vid)) and finally Black & white Stripe (Never say Die & Hard Road VID) this is a different one to the JD Humbug further up the thread. I think he got the humbug one later on during the Never Say Die US tour. Never uses that one on all pics I have seen for UK tour (Always the JB). Geezer reckons that he got the cross inlays before Tony (his idea). As for the Never Say Die Ric. I have quite a few pictures from the recording sessions and only the Ric is in any of the photos. As for the BC Rich Eagle, when he says it was custom made for him, He probably means he ordered it, as they were all pretty much handmade. Also it did not have EMGs, I am certain that they were loaded with stock Dimarzios. All photos from programme etc support this... I was very lucky to see Sabbath up close at Newcastle on the "Die Young" tour 1980 and Mob Rules 1981 tour. Interestingly (to me perhaps not anyone else) about 5 years ago I did see an all black BC Rich Eagle with ebony fretboard cross inlays, a cross on the Headstock and EMGs. So perhaps he did custom order an Eagle with EMGs? but I dont think he ever used it in studio or on tour.I got a Born Again programme and he seems to be using an Aria and the standard Eagle at this time.