I think it could be made to work. The barrel would be suitable steel, not ordinary cane metal.
In a different sort of cane gun, did you see, The Day of the Jackal, where the gunsmith made up a gun that would pass for a crutch? Very impressive!
BTW, I exchanged letters with the real Geoffrey Boothroyd and read his articles. About 90% of the posts on the Net about him, Fleming, and the Bond guns is heavily flawed. For one thing, Boothroyd never advised a PPK for Bond. That was Fleming's idea, as he liked small autos. B. actually suggested the S&W Centennial Airweight, with the Colt .45 under the dash of Bond's Bentley being replaced by a S&W M-27 .357, in part to have partially interchangeable ammo.
In his epochal work, The Handgun, Crown Publishers, about 1970, Boothroyd said the the S&W Model 60, the stainless Chief's Special, was rhe ideal Bond gun. But Fleming had died before it came out, so it was a moot point.
None of the authors authorized to write Bond novels after Fleming's death ever captured the character right and it was usually tedious to read their books. The last I read also had a dose of the Political Correctness of the movies, which usually have little in common with Fleming's books except the title and the very basic plot. The books were better.
Fleming carried a Baby Browning .25 while an agent. He had faith in it, given its obvious limits. An OSS agent who wrote about her experiences during WWII carried a .25 Beretta and killed a knife-wielding gypsy with it. See, The Spy Wore Red and other books by Aline, Countess of Ramonones. (She was American, but married into the Spanish nobility.)
