Sharp Reisz microphone

The "Sharp" brand name stems from the 1915 invention of the "Ever-Ready Sharp Pencil," a mechanical pencil, which later inspired the company's focus on innovative electronics. The company officially changed its name from Hayakawa Electric to Sharp Corporation on January 1st, 1970

The marble block, mounting loops and terminals appear to be identical to the Mikasa model number 50, as seen on ebay. They are essentially the same microphones with different front grills. The Mikasa corporation was founded in 1917 and mostly focused on rubber goods, later specialising in sporting goods.

You can read more about the history of the Sharp Corporation here.