As you know, the majority of kayaking related video out there isn't that good. It all seems to be short whitewater snippets or really bad attempts of people trying to roll their kayak in their backyard pool.
In my search tonight, I found this interesting little video by Legacy Paddlesports. It is an employee training and recruitment video and seems strange to me why it would be posted on a video sharing site but oh well.
Generally speaking, it is a little dry (what employee training video wouldn't) but there are a couple of interesting sections that might be interesting to you. In the video, they pull back the curtain and show footage of the factory floor and show how they make roto-molded boats and composite layups.
If you get board of watching it, jump ahead to about 2:50 for some hot boat manufacture action. Sadly, it is safe for work...