Don Stoner, a name well known in most Amateur Radio circles, was also a pretty popular fellow with 11 meter folk back in the sixties and seventies. Occasional columnist, Don had a vision of what radio operators around the globe were looking for and the vision brought forth the Stoner Pro-40, and Stoner Pro-10.
Pictured above is the Pro 40, one of the rarest solid-state rigs you'll ever see (or not see). Along with another high-end collectible, the ARF 2001, the Stoner Pro-40 is relatively scarce, and those who own them don't like to see 'em go (I outta know, I have two!). Sure, you'll hear someone on-the-air, or perhaps along the Internet knocking the Stoner and professing the better rig a (ick) Galaxy, but usually those guys are the ones selling the new product and would prefer to steer you towards a new purchase anyways.
Of course, the Pro-40 wasn't for everyone, mostly because it was a single-sideband only radio (that's right, no AM). There were a variety of accessories to add to it, including an AM "module" (which was really just an AM transceiver. Other accessories like the scope were something you usually found only on ham equipment. Accessories are harder to find that the radio it seems....I have two radios, and only one accessory (the scope), but eventually I hope to have a complete set for the museum.
Channel selection was by electronic push-button (UP, DOWN) and that big knob in the middle? Your "Clarifier". Transmit audio is very good, especially with an Astatic mike (I prefer the Silver Sidebander) and between this and my ARF2001, most seem to prefer the Stoner's audio over the ARF.
The PRO-10 was exactly what you think it would be, a 10 meter transceiver, and I only know of one person who actually owns one (he sent me E-mail not too long ago).
In an Update: Don Stoner became a Silent Key on May 04, 1999, in Florida, the end result of a lengthy illness. Wherever you may be, on whatever sunspot cycle you made be riding - "Thanks Don, for letting us buy into a little of your dream for Single-Sideband excellence....."