https://www.veterans.gc.ca/eng/remembrance/medals-decorations
The link from Veterans Affairs is a pretty exhaustive list of medals that Canadians could have been awarded.
As for your grandfather's medals; the France and Germany Star, the Italy Star, the 1939 - 1945 Star, the War Medal 1939 - 1945, the Canadian Voluntary Service Medal (CVSM), and the Defence Medal.
I believe the order that they are mounted in is technically incorrect, and should be (left to right) the '39 - '45 Star, then the Italy Star, France and Germany Star, Defence, CVSM, and finally the War Medal.
https://www.veterans.gc.ca/eng/remembrance/medals-decorations/wearing-medals/ww11medals
Being that your grandfather served overseas (campaign stars being awarded) he would have qualified for the Overseas Clasp to the CVSM as well. These are fairly easily acquired, if the original is missing, and should be mounted on the CVSM ribbon.
As for reconditioning, less is more, generally. Of course, it is up to you and your family how you would like the medals displayed. Do you want them polished like the day they were issued, or do you want them preserved keeping the patina of age but kept from tarnishing? I'd suggest using a product like Lee Valley's Conservators Wax or Renaissance Wax (which when applied gently cleans as well as leaving a protectant layer) and can be buffed to a dull sheen. This is something you can easily do yourself, as long as you take your time - and it will save a great deal of expense and stress, especially not having to worry about having the medals in someone else's care.
As for the mounting/glass; take the works down to a local self framing store (usually an art store of some kind - search around and you'll find something) and get them to measure the frame up for a new piece of glass. You could also get a new frame made up, if you were so inclined.