I think you said that this is your first paddle. Given that, you're probably going to modify it, so going overboard trying to protect it doesn't make sense. Epoxy coating the tips is the most I would recommend. Color-wise, the epoxy will look very similar to oiled wood, so the tips won't be especially obvious. OTOH, you could tint the epoxy white and make it look like bone tips from a distance.

One other suggestion; judging by the pictures, it appears that your block plane desperately needs to be sharpened. It shouldn't be gouging the wood like that.

Thanks, Bryan. Good to know about the epoxy color. I like the idea of white tips; in fact, I briefly considered trying to find cattle should blades at a butcher shop and then boil/bleach them for the tips. But then attaching them would still be a giant puzzle even if I could acquire those.

The one thing that worries me about the epoxy is that I'd eventually have to redo it if it gets a crack, unless I use fiberglass under it. And it makes the whole thing more complicated in terms of buying the supplies. My one decent paddle got lost or stolen, so I'm about ready to get back out on the water and be done with paddle making for now.

BTW, it was thanks to a 2002 post of yours that I got the idea of using tung oil/thinner/varnish. So now (given the above) I'm leaning toward just the oil/thinner.

I did sharpen the plane a couple of times with a metal file I also use for tuning snowboard edges. But maybe I did it wrong. It felt plenty sharp, though. Maybe I didn't do it enough.