Escrima

[Scythe13]

Off the top of my head, I remember 'hearing' about a guy down London whose walking stick is styled like thick bamboo, and if you look closely, has a joint in it that can open up and abrakadabra [insert magic sound effect] you have 2 short metal fighting sticks, not too dissimilar to Escrima sticks.

I have also seen some walking sticks that have a twisty handle that is really a sword handle and the blade runs most the length of the walking cane. For the gentleman whose up for a morning duel haha.

I'm sure it would be possible for a person to pretty easily build their own walking-stick-sword-cane-fighting-stick-thingy. Or just get a metal pole stuck through a cane (or just a really hard wood, or even a painted metal cane) and just walk with a limp. BP with his beard could very easily pull off this kind of look.