I only have to show my PAL when I'm window-shopping for the guns that can shoot into space.
Cannon
Italian Sporting Goods in Vancouver, BC does not allow non license holders to inspect any of their firearms. This was with my father before I actually started the process of getting a PAL, I don't disagree with the policy now, but they made it seem like it was against the law. I walked out feeling stupid/embarrassed.
Seems like an excellent idea to me, but then again that's exactly what I've been doing (albeit with a NR PAL coming, not the RPAL).
Aside from stores, I would recommend you visit gun shows and hunting/fishing shows. I've visited three shows in the last two months and one store near Ottawa and have never been asked for a PAL or RPAL. I was able to handle several black guns to check the ergonomic fit (Tavor 21, HK SL-8, Robinsom Arms XCR-L, ISSC Mk 22, Benelli MR-1, etc...). Be polite, ASK before handling the weapon and be upfront that you're checking the fit while waiting for the PAL to arrive. The hunting show people in particular are sports enthusiasts and are usually quite understanding.
Mind you, try to have an idea of what you want first... don't ask to handle all 30 guns in their display!