Thank you both for your help.
Fortunately, I found a Krause publication at my local library yesterday

. It's been a great help thus far.
According to the book, all four coins are indeed 50% silver. Apparently the bottom two (the Moose & the Ironworks) were also minted in a proof as well as a non-proof coin (both are .500 silver). From the appearance of the two, I would say that they are the proof coins - very high luster fields & devices much like US proof coins.
Is there anything else I should be looking for in determining whether they are proof coins or not?