Two experienced posters displayed pics of their unwanted tips, some brass one from Rollin Thurlow and a copper one from Ross Bros Canoe Company
An online copy of Popular Mechanics (July, 1934) has a an article entitled, "It's Easy to Repair a Canoe". The pic on page 109 shows a metal tip pattern with instructions to nail it onto the front of the blade and clinch the nails on the back to prevent splitting.
Metal Tip Repair
The general consensus on the WCHA forums was that such paddle tip protectors actually cause more damage as the nail or staple holes permit water penetration and eventually lead to rot. For some paddle makers, the old-time aesthetic appeal is a desirable addition.
The beautiful paddles crafted by Doug Ingram at Red River Canoe recreate this appearance with modern materials. A post from his blog, Wood Be Creative shows the process of routing out the blade tip and filling in the tip with coloured epoxy set in a mold. This gets sanded down to the final appearance.
While I've got no intention of damaging the tips of my paddles with nails or staple guns, I'm intending to add a woodburned, pyrographic image of this tip design onto the Northwoods style paddle I'm working on. We'll see how it turns out.