MAGNATONE MARK III STANDARD specifications:

MACHINE HEADS Enclosed “Safeti-String Post” Machine Heads. Three-a-side configuration.
NUT: Special Guitar Nut for greater response.
FRETBOARD: Accurate professional fretboard with fast action frets and seven position dots.
NECK: Exclusive Magnatone steel cantilever suspension in neck. Specially designed fast action neck, made of selected Honduras Mahogany.
BODY Contoured body for player’s comfort. The full cutaway body measures 15-1/8 inches in length., 11-1/8 inches in width, and is 1-¾ inches deep which enables the player to reach difficult positions easily. The body is made of light weight hardwood for ease of handling and balance, finished in "Desert Sand" scratch-resistant finish.
PICKUP: Completely adjustable on fully shielded pick-up. Uses Alnico VI magnets.
BRIDGE: Magnatone’s exclusive Perfecto-Tuned Offset Bridge for perfect intonation and harmonics, made from beryllium copper. The fully enclosed bridge is completely adjustable four ways to suit the individual player's demands.
CONTROLS: Straight linear volume and tone control with Magna- tone's super-sensitive pick-up enables a complete tone color.

SOURCE: Magnatone catalog 1956.