Seeing the glue lines on it I wonder what the material and adhesive is. I work with a lot of "laid-up" foams and there are few assemblies I wold suggest for a watercraft.
I recently produced patterns for a similar one that will be produced locally here in N. Texas. If he continues with his original plan, it will be of hand laid fiberglass with a decent load capacity. I have no idea about his price. If you were not already into and educated about the potential of today's fishing kayaks, I can see the appeal of one of these. After all I DO still have two 11' aluminum pontoons laying in my side yard waiting to become a small,,,,, something..
When I first got into cnc I wire cut several foam miniatures of that (about 6' long) I used as back up craft for my wade fishing on the coast and crappie fishing the spawn.. I mainly used them to drag along all the same kind of stuff we put in our yaks. Food, bait,stringer, rods, extra gear. etc.
There are a lot of decent options if you want a hybrid that you can paddle. The best efforts I have seen isn't retailed here locally, but is called a Kiwi. Not too expensive and some of the virtues of a kayak,, but definitely not all. It is from waaaay up north, but they ship to a dealer in Louisiana regularly.