I have a music centre with a C142R with some small cosmetic differences from the image shown (4).
attached are a couple more, the P157, small C114 and the C141R1 , my favourite BSR arm; a lightweight type with small head, which is like BSR's equivalent of the Garrard 2025TC.
this site has loads more pics. I'd like to one day get a copy of the story of BSR book, seems essential if you're interested in these decks.
As concerns that model with the stud which senses the disc size from below, that was common in the Argentinian Wincos.