General thoughts
Thanks for the suggestions! I fixed the Mandate&Mission section - hopefully it flows a bit better now? You're correct that the slim sections you mentioned are just waiting for me to type up the info I have on them.
I'll look up some notable private records, I'm sure they'll be some interesting ones. I'm thinking Louis Riel would probably be a good person to mention...
I like the layout/organization of your page now - I definitely think it reads easier. One nitpicky thing: in most of your headings you says Type of Archives: Example (Provincial Archives- the Archives of Manitoba etc.) However you don't follow this format for University Archives, presumably because you talk about more than one example. I would probably suggest just making your headings Provincial/Municipal/University etc. Archives and leaving off the specific names. However, you want to do it though, just check the consistency.
Otherwise your page looks great!