The SME 3012 type I has a rotating headshell socket, good….the candid eye could think that this allows to play between star and square pin configurations.

Not that easy!

You can see in image below that if you rotate the socket for the headshell then the pin configuration is off. So you need to rewire or alternatively make a complex box that will switch wiring.

The only know tonearm that had the particularity of having a rotatable head-shell socket was the SME type I. The type I was made for broadcasting purposes but never really succeed in that field. The idea was that it would sell to all studios using star or square pins. The result was the type II that was less expensive to produce and focused on audiophile market of the day, this having the permanent square pin (aka SME).

The design was not intended to be switched from one to another, the documentation of the type I gives the various wiring at arm connector, designed to be wired once and for all.