I just bought a used dagger dimension recently, the boat hasn't been used for whitewater in years, but was originally outfitted with these seats:
they were made by bob foote, have a black watertight box strapped to the front, and the entire seat is a compartment (the white round cover spins off).. I haven't seen anything like these currently produced.. any idea how old they are?
I remember those being pretty current when I started paddling in 91. Not sure how long they had been around before, though. You could contact Bob Foote through his web site : http://www.bobfoote.com/contactus.htm