Hannes: going over your posts I made up a summary so I can get the whole thing into my mind at once:
-siton outrigger, has to be stored in a bag, hip problems, hoping to convert plan for an oc1 s&g to a folder.

I'm not familiar with OC-1 canoes but the ones I've seen are narrow enough to make a typical Greenlander look rather fat. Not beamy enough to provide a comfortable place to sit on for a guy with a hip problem. I had a hip problem for years so I sympathise. Also a typical OC-1 seems too long to fold into a bag and assemble in a reasonable time, too many parts. I have searched for an OC-1 design to start from, so have others according to web pages I have found, and there seems to be nothing out there.

So perhaps we should be looking at a boam of more modesst length and generous beam, still slick of shape, that folds, probably with a matching ama that is almost as long but much narrower.

This a problem I looked at long and hard about 10 years ago and I was never able to come up with a good design despite joint experience of boat design and folding structures of the kind used in Space. The Klepper and yost boats take too long to bag and unbag, the Klepper has a poor performance in the water and no skin boats I have tried keep up with a hardshell. A sectional boat (http://marcusdemuth.com/3piece.aspx) provides the best performance option and gives the ability to fit inside a car trunk, but it doesn't collapse down to fit in a bag.

Back then I made this list of commercial folding boats illustrate various folding methods although they may not suit your needs; some may have fallen off the web my now -

Taiga: Vancouver based, sell and/or build various brands, using skin over frames of wood and/or aluminum tubing
Porta-Bote: folds flat lengthways
InstaBoat: folds flat lengthways
Folbot: skin over frames of wood and/or aluminum tubing
Trak: looks like skin over wood frame
Kero: distributor?
Nautiraid(?): skin over frames of wood and/or aluminum
ToteNboat: angular boats formed from stiff sheet, uses Z-fold to seal gaps, curved bottom, side rails
FirstLight: carbon composite tubing
Feathercraft: skin over frames of wood and/or aluminum tubing
Fujita: skin over frames of aluminum tubing
Pouch: skin over frames of wood
Pakboats: (e.g., Puffin) skin over frames of aluminum tubing
Flapdoodle: plans only, plywood sailing dinghy, folds flat lengthways, uses PVC sheet hinges
Foldlite: hardsheel, folds in middle
Taimen: (Russian) skin over frames of aluminum tubing
Longhaul: wood frame
Origami: generic name for boats shaped by folding some kind of sheet