You do realize, of course, that all that weathering and staining on the outside of the hull isn't going to go away when you clear-finish it with fiberglass. The resin will actually accentuate the differences and make the contrast between clean wood and weathered or stained wood even more obvious. The planking on those is too thin to tolerate much sanding (especially if you concentrate on trying to clean up the inside) and you don't really want to sand into the tack heads. Much of what made the Trappers attractive was that the planks were carefully selected for uniform color and it was all fresh, clean cedar when the skin was applied. As for rocky creeks, fiberglass is somewhat more scratch resistant than filled canvas, but by no means abrasion-proof or impact-proof. This brings up the question of which is more durable - a boat with a moderately tougher skin but one where it is extremely difficult to repair or replace any cracked ribs or planks from rock impacts, or one where the skin is a bit softer, but any part on the entire canoe can be replaced over the years? With the combination of the questionable cosmetics of the old wood and the mention of use in rocky streams, I'd save the glass to make a stripper sometime. I'd cover this one with canvas instead - and spend my energy trying to get the interior wood looking good again, because you don't have enough plank thickness there to clean up both sides for a good looking clear-finish.