I should have noted the painted rib tops -- removing paint from them will be virtually impossible, because it has almost certainly been sucked into the grain of the cedar -- deep enough in that neither stripper nor simple sanding will likely remove the end-grain paint completely, and given that the paint is black, I think you are going to be stuck with black rib tops -- unless you want to cut the sheer down perhaps 1/8" or a bit more. To do this, of course, you would want to remove the gunwales and decks. If it were me, I would probably put fresh black paint on the rib tops after stripping the gunwales -- even varnished, the rib tops tend to look dark.
I suppose you could try to strip the gunwales in place -- the chief difficulty would be to not get stripper on paint or varnish that you do not want to strip. I'm not sure how much, if any, protection masking tape might give -- I assume that it would not give much, and that at least some touch-up painting of the canvas would be needed -- but if you are planning to repaint, or to paint a decorative stripe under the gunwales, protecting the exterior paint wouldn't be much of an issue -- just paint over any minor damage.
However, taking the outwales off is often not difficult, if the screws are in god shape -- the task is a bit tedious because the paint must be dug out of each screw slot before you can back the screw out -- but still may be worth the trouble.
Protecting the interior varnish would be harder -- but again, if you are planning to varnish, perhaps not much of an issue also. Removing the inwales is much more of a project.
Given that the thwarts and seat frames are also painted back, I would strip them first, just to see what I was dealing with, and to see how well or how poorly the paint comes off. It's hard to tell the condition of the paint and varnish from the photos posted earlier -- maybe there is just a lot of dust and dirt that can be washed off, but -- it looks as though a new coat of paint would not be amiss, and it looks as though the interior varnish has seen much better days -- a new coat or two of varnish seems called for at a minimum, if not stripping the old varnish and re-varnishing anew.
Are you planning to redo paint/varnish in the next couple of years, or are they better than the photos sow and are good for a longer term? If they are going to need to be done in a relatively short time, but not right away, you might consider painting the decks/gunwales a more attractive color until the time for a complete paint/varnish do-over is done -- especially if the complete do-over will include a new canvas. Stripping interior varnish is often done at the same time as replacing the canvas. It does look as though there are at least two coats of paint on the canoe (the top coat seems to be peeling/flaking), which suggests that the canvas may be quite old. for a discussion of painting over old, flaking paint, see <
http://forums.wcha.org/showthread.php?9711-Repainting-my-16-Faber&highlight=flaking+paint > and the links in that discussion.
