Interesting that the seller (meba2233, as Æoliandave has noted) says in the listing that the hose is a "brown" shade. When these hoses were new, they were dark gray with a lovely silvery sheen. Over the years, the color in them "morphs" to various hues due to exposure to sunlight (and, lesser so, to the dye color changing as well), but most often to a dark maroonish-gray color. I have several of these hoses but only a couple of them are still the correct color, and that's because they have been kept out of sunlight for most of their existence. See photo for a good example.

This particular style of hose, with the metal swiveling handle end and two rubber cuffs, came out on the 509 and was used through the 515. (The color and pattern were introduced with the 508, but the handle end had just a rubber cuff into which a short plastic tube extension was inserted.)

Norm, the safety switch was the same from the Model C (and R) through the 515. While the overall style of the machine-end hose coupler changed somewhat through those years, they are all interchangeable in terms of connection to the machine.

The safety switch (and, thus, hose coupler) changed with the Model 516, the all-new model with the streamlined motor housing and dark-red color for the attachments.