Wow, those are extremely cool ideas!
Your image of Puddleglum's sword was similar to what I'd been thinking of, which is something in the neighborhood of a falchion (or a German Grosse Messer):
https://www.google.ca/search?q=falchion ... 8640666831Just something plain and peasant-ish, a heavy chopping tool that Marshwiggles might use like a machete to hack their way through the marshes.
I love the idea of having kukris used by Calormenes! (I have one myself, so yes I do love them). Using them would provide some cool possibilities for action sequences, with people throwing kukris like axes! (It's been done for real.)
As for giant swords, I'd been thinking about Viking
svards. Something a bit rough with Northern vibes, and a somewhat shorter blade to sort of accommodate the steel shortage problem.
I know "Catsbane" (let's just keep going with that, OK?

) was likened to a rapier in the books, but if Narnia is late medieval, those fancy handguards might look slightly out of place. What about a sword breaker? :
https://www.google.ca/search?q=sword+br ... 8641709259 They're light and slender like a rapier, but the hilt looks more consistent with the cruciform design on the the other Narnian swords. (After all, is a mouse really worried about people hitting his paw while swordfighting him?)
I'm wondering how you can come up with a design for Rhindon that doesn't end up too strongly resembling the Walden version or one of the various lion-themed swords from Game of Thrones. Perhaps if the entire handle was overlaid with gold?...