Gibson promo / specification sheet for the Firebird I guitar, published in 1963. The Firebird I was certainly a nicely built, but ultimately simple electric solid body guitar: just one pickup and a solitary volume and tone control. The 'special construction' mahogany body mentioned refers to the neck-through build of these early (reverse body) Firebirds. Although this sheet is undated, the price quoted ($189.50) is accurate for the period July-August 1963. Note that custom finishes (Cardinal Red, Heather poly, Inverness Green poly, Ember Red, Polaris White, Pelham Blue poly, Frost Blue, Kerry Green, Silver Mist poly, Gold Mist poly) are available at a $15 premium.
The specifications for the 1963 Firebird I were as follows: mahogany body, through mahogany neck, unbound Brazillian rosewood fretboard with pearloid dot inlays. Nickel plated hardware, Mini humbucker with volume and tone control. Sunburst nitrocellulose finish. 24 3/4" scale. 22 frets. TPBR-85N bar bridge / tailpiece. Sealfast MH-570T 12 to 1 banjo-style tuning keys. 'Gibson' celluloid truss rod cover. The other three Firebird models come with a leather strap - not mentioned, so presumably not included for the Firebird I.
Similar sheets were also produced for the other guitars and basses in the Firebird / Thunderbird series