-- Last Updated: Nov-06-12 9:21 AM EST --
The gunnels on this one are aluminum, but I have done this with vinyl gunnels on Wenonah and Mohawks.
Looks like you already have expert advice on removing and replacing a few rivets. It's NOT hard, promise. Drill them out, tilt the plate, and wiggle it out. Replace rivets.
Now, I've used these on drilling through vinyl and aluminum gunnels to replace seats in Bell, Wenonah, Esquif, and Mohawk canoes:
The flanged washers "Spread the load" and keep the bolts from pulling through and I'm NOT a little guy. Don't skimp and buy flanged washers from the "Big box" stores or you will find they rust and need replacing. Learn from MY mistakes (LOL)!
I like the "Truss" like seat hangers, but I always trim mine since I like to kneel. They will move around less and provide more support for your seat. I think very highly of Ed's canoes, and get all of my seats, thwarts, truss mounts from them. Here's their link:
It's not that hard to re-do the seats and I highly recommend it. I HATE those cheesy metal seat hangers as do most paddlers; do you hear that Wenonah and Mohawk?
Oh, and IF you do use a skinny washer and have a "Pull through," in the gunnel, even that is easily fixed with a bit of fiberglass work to the gunnel.
Don't sweat it, it's not that hard even for those of us WITHOUT "Handy man" skills!