Found this ST4B on the web. The add is in Swedish, but says it's a 1985 ST4B in good condition, but needs new paint. Price in Swedish krone is Skr 65,000.- wich is about $ 8300 USD.
http://www.veteranborsen.no/Annonser/Retro/2007/Fra 80327-07/80329-07/Viser.htm
http://www.veteranborsen.no/Annonser/Retro/2007/Fra 80327-07/80329-07/Viser.htm