I have the 9" Mission version of this 12" Jelco (Jelco made it for Mission). They use Linn/Jelco mount. Removable headshell
vinylengine
https://www.vinylengine.com/library/jelco/sa-750l.shtml
Some have surface mounted screws. The one above looks to have threaded holes for machine screws from below. My Mission came like that, I drilled my holes all the way thru and used wood screws from the top into my wood deck.