Those edge markings identify this as an issue of the Franklin Mint. The "72" indicating an issue date of 1972, the "P" for Proof issue, and "STERLING", of course, for 0.925 fine silver.
With that in mind I pulled out the Guidebook of Franklin Mint Issues- 1982 Edition
which identifies this as the last of a number of special issues by Franklin Mint Canada and Wellington Mint. This medal commemorates the 100th Anniversary of John McCrae's birth. The Guidebook confirms that these were serially numbered so the 00012 means at least 12 examples of this medal were issued. The Guidebook does not indicate, nor could I find elsewhere, the total mintage. Likewise, I've thus far been unable to find out who "GV" might be.
Hope this helps.
Thanks for sharing this. Always fun to dig into these!