When I was helping my friend clean out his grandfathers homestead, there were about 15 walking sticks ... at least 10 of them had hidden compartments for flasks of whiskey. 3 of them had concealed daggers.
We were very impressed. We thought he only used the sticks to help his knees ... but ... he was a clever old scotsman.
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I think I want a dagger one! I would be cock of the walk!!! OR in prison. They are mighty funny about knives in Scotland sigh
Just say its a Sgian-dubh and that your knee is too sore to put it in your sock. Any Scot will empathize with you and give you a free pass.
But, I'd go for the flask myself. Any time you think you should be sticking someone with your dagger ... have a drink. (pretty soon, you'll be walking with two canes)