Well
Truth is I have a good looking face----for radio.
I wouldn't bother with temporary decks, that's what the duct tape is for. Wrap up the ends. The cheapie one inch pine, or whatever have you need be roughly long enough to go end to end. You'll need four. Oh, another idea. Some folks use plastic wrap to fasten up bundles of stuff. Syran wrap?the temp inwhale can be used for to attach a 1 x 2 as a thwart. Or two. And deck screws self tap. No pre drill. I did not have to travel far so did not fuss much with my temp 'whales. Put the screws through ribs or not. I would not think that it matters. Basically you will be doing alot of repair from the sounds of it. you may even lower the 'whales if your canoe is deep enough to start with.