Congratulations.
I, and two other members from my OMLT team, were awarded the MSM and were not allowed to wear the medal, or ribbon, until it was presented by the GG
The MSM is a national award therefore it will be published in the Canada Gazette, hence "gazetted". Once the award is gazetted, you may use the post nominals " M.S.M. "
I do not know how recent the announcement was, but will assume that your CO got a phone call from higher sending congrats to you for the award. A RO entry will follow plus several personal letters from several layers up in your chain of command. A letter from the Governor General Of Canada chancellery office congratulating you and asking how you want your name etc to appear on the scroll, and stating info on the Investiture Ceremony will follow.
The Canada Gazette Part 1 entry will occur concurrently/soon after you were notified.
You can wear the undress ribbon on you ribbon bar as soon as the chain of command notifies you of the award. In fact they should have got a ribbon made up and presented to you, with photo, at work.
Does not have to be a parade. You will, along with a guest be attending an investiture where all the formal stuff will happen.
Have the unit clerk open up a Conduct Sheet for the award, or to add the award entry to previous behavior where you got caught!!
You will not be wearing the medal of course, cause the GG's still got it. Buy a miniature now if you would like.
Wearing the ribbon of an award that has been gazetted is a long standing tradition/custom/practice. Thousands of service pers in WWII, especially air crew, wore a gazetted ribbon and unfortunately never lived to attend an investiture. Whoever is saying you can't wear it, is wrong.
Years from now your relatives can go to the GG's web site and search you name and it will pop up. Even for the Diamond Jubilee Medal!!
You are now part of Canada's history. Congratulations again!
P.S.You should search for the Canada Gazette Part 1 entry to keep as a souvenir.
Photo att is the Canada Gazette Part 1, Government House promulgation of several foreign awards incl US MSM's. (I knew a Vunak. Wonder if it is the same.)