Wilderness Pongo 140 upgrades

Mine is about 5yo. Seat back pull cable clutch has broken.
Is there a better seat for this? More padding for a boney butt. Or should I just fix the issue and if so, what is the part called and where can I find it?
Is there an aftermarket fitable top drain plug?

You could try Harmony Gear. They have a ton of stuff for Wilderness Systems kayaks…

http://www.harmonygear.com/boatparts

thanks for the link