Standard Radio made high quality commercial and amateur radio equipment in the 70's and 80's. I believe it was acquired by Marantz, then by Yaesu, then by Motorola. Something along those lines.
Superscope bought Standard Radio in the mid '60s, and used its factory to produce Marantz and Superscope products. After many changes (including a stretch where it was owned by Philips), the factory still exists and is now Marantz Japan, part of D&M Holdings.
The commercial radio part may have been spun off to Yaesu and Motorola, as you said.