The S-50 was launched in 1963 as the Jetstar; a cut-down version of the Guild S-100 Polara and Guild S-200 Thunderbird. These were Guilds first solid-body guitars, and they were featured in the 1963 Guild catalogue.
Both the S-50, and the S-100 changed over the years, the biggest occuring in 1970, when they aquired the Gibson SG shape. The names Jetstar and Polara were dropped at this time, in favour of just the model code S-50 and S-100
It had a mahogany (or alder) body with a set mahogany neck with a rosewood fingerboard. Dot finger board inlays and no inlay on the headstock. It had just one pickup and simplified controls (just volume and tone). Most had a Guild humbucker, though instruments with a single coil pickup may also exist.
The sixties versions had the Guild asymetric headstock, or a 6-a-side headstock very similar the the Gibson Firebird / Thunderbird guitars. It was available in Cherry as standard and in a range of special order colours: Emerald Green, Honey Amber, Ebony Grain and White.
The redesigned SG-style model had a more traditional 3-a-side headstock, and was available in only Sunburst, Cherry, Black, Walnut, or Natural.
The description below comes from the 1966 Guild catalogue - Americas Finest
Pleasingly contoured body is designed for comfort and ease of handling, is 13 3/4" wide. 17 3/4" long, only 1 9/16" deep. Has the famous Guild fast-action neck with 24 3/4" scale and 22 frets.
This instrument has a single built-in Guild "Frequency-Tested" pick-up with individual adjustment screws and separate tone and volume controls. Distinctive new Guild integral tailpiece-bridge combination, with swing-off cover, is adjustable for height, tension and intonation.
This easy-action solid body guitar is highly recommended by teachers for student and other amateur use. Factory-fitted with Guild Strings.
The description below comes from the 1975 Guild electrics catalogue
If one pick-up is all you need, consider this solid body that gives you the essentials for both lead and rhythm playing. You get the same Guild Humbucking Pick-Up as on the other guitars in the "S" series, the same body shape and quality finish—plus a fine neck and fingerboard. All of this at a moderate price.
Details: Contoured all mahogany solid body. Guild extra-fast, very thin mahogany neck with fully adjustable truss rod. Rosewood fingerboard with inlaid mother-of-pearl position dots. Natural headplate. All hardware chrome plated. Guild machines. Guild AdjustoMatic 6-way bridge. Tailpiece of solid brass. Black laminated pickguard. 22 frets. Neck joins the body at 18th fret. Guild E-220 Sidebender Strings.
Electronics: Single chrome plated Guild Humbucking Pick-Up with individual adjustable pole pieces for each string and 3-way tilt adjustment for accurate pick-up placement. Separate tone and volume controls.
Dimensions: Body 1 7/8" (32.7 cm.) wide, 16" (40.6 cm.) long, 1 5/16" (3.3 cm.) thin. Overall length 39 3/4" (100.9 cm.). Scale length 24 3/4" (62.8 cm.). Neck width at nut 5/8" (4.1 cm.).
Electric guitar advertisements originally published from 1971 onwards. Click on the images for larger copies. Check out other vintage Guild advertisements
Guild S-50 - New Anti-Hum Pick-Ups on All Guild Guitars and Basses (1971)
This advert from December 1971 doesn't say much; letting the guitars do the talking. From Top to bottom: M75, S-50, S-90, S-100, JS bass II and JS-bass II fretless