Alex wrote: Faltboote in German simly means "foldable boat". If it was a "Folbot" brand from 70s (US, formerly British, company), I doubt it was foldable.
No, it could have been a folder. The Folbot Super tandem (double) was produced, typically with a vinyl skin, as a folder (TSF) or a non-folding boat in the form of a kit (TSK), up into the 1980's. The Super is a very large boat for a sea kayak, being even larger in beam (but about the same length) as the current Folbot Greenland II, and heavier, despite the use of many wood parts (Baltic birch plywood and/or marine plywood, I think).
Here is a link to a series of posts in the Folbot Forum detailing the experiences of a Utah couple with their 1970's TSF: http://folbotforum.com/viewtopic.php?t=2135
There is a bit of a "cult" following on these boats, with some devotees restoring some pretty old, dilapidated craft, including new skins, almost excleusively of the non-folding variety. Vinyl is not as durable as hypalon for a skin, however. The boats are somewhat of a maintenance headache, but these folks love them.