Lol, I don't know anything about Canadian coins, I just assumed it was a proof from the photo. Now that I know it is a mint state coin I will change my guess to MS65 DMPL
I just looked and it does seem that Canada made a proof in 58' I have always liked Canadian coins, but hadn't bought one slabed till today.
I'd double check that. This is what I understand: The Canadian mint has been producing Proof-like Sets of coins since 1953. These are not actual proof coins, but they are high-quality strikes from normal 'business' dies.
Just an fyi, see 'striking style' near bottom of page http://www.calgarycoin.com/modern/canada.htm#grading
Someone on CT asked that other coins than, Morgans, be part of GTG. I really bought the coin because it jumped out of the case. Could have bought the 5C an 50 C also. Thanks @jj00, that helped for clarifying what the PL means. It still Puzzles me why, if it is an early die state. Why the heavy polished lines in the Planchet? To me they aren't distracting.
If I can take some decent shots of mine I'll post....no promises though, my photos are pretty poor...