This is another ultra rare prototype. According to a note by Dale Hyatt in his sales log for the serial number of a known S-300, there were less than 10 built and most likely only 4. There are 2 serial numbers in the Registry of the Guitars by Leo (GbL) website, both also displayed in its Gallery: S/N G009365, with May 1982 date stamps in the pocket and on the neck heel, and S/N G009391, entered in the sales log on 5-28-1982 and the one associated with the aforementioned note. The earlier blueprint in the GbL Gallery, drawn by George Fullerton (GWF), has a revision date of 8-17-1981, 10 days after George drew up the blueprint for the F-150 prototype. The later blueprint, also drawn by George, has a date of OCT-19-1982, 5 months beyond the production dates quoted above. The Gallery pictures show both entries with a Tobacco Sunburst body, white enamel pickguard, and black powder-coated control panel housing the PTB wiring harness and preamp. In the S-300 prototype 2 other G&L models seem to have come together again, now the F-100E, which also has a preamp, and the S-500, with its similar looking triplet of square corner single-coil pickups. Beyond the quoted material, not much else is out there on the S-300.