Neale,
Looks like you have a nice collection of fine airguns there!!

Needfull,
The only "cane gun" I ever saw was about 5 decades ago,It was made by Remington and was in 410.

Stuff of that sort is now list as NFA but I guess that an airgun cane would not come under NFA rules being that it is an airgun.

I might check into something like that.

Wayne