Up for bid is a vintage Thunderbird Formula/Signa Boat brochure. This is one of the finest one I have seen. It is in perfect condition. It shows pictures and specs on 19 different models from 1978.Formula 26 Formula 255 Castaway Formula 255 Vanguard Formula 255 Liberator Formula 255 Freedom Cruiser Formula 233-C Formula 233-H Formula 233-F Formula 233-CL Formula 20 Formula 20-CL Formula 18 Formula 18 Bow Rider Signa 20 Signa20-C Signa 18 Signa 17 Signa16 Again this brochure is in excellant shape with only the dealer stamp added. Pier 31 Harbor Inc. in Camdenton Missouri at Lake of the Ozarks.