Hi Helen,
Unfortunately, I don't think you are going to find much in the way of BMDs for Manitoba. There is no central registry as there is in the UK -- each province handles its own records and some provinces are more research-friendly than others. Also, Canada has very strict privacy laws and they vary from one province to another.
In Manitoba, the only public records are births more than 100 years, marriages more than 80 years and deaths more than 70 years. The vital stats site is
http://vitalstats.gov.mb.ca/Query.phpThe Winnipeg Free Press has a subscription archive site where you can search old newspapers for articles or notices of births, deaths and marriages. I think there is a weekly subscription plan for around $10 Cdn. The site is
http://archives.winnipegfreepress.com/I'm afraid I can't think of any other avenues for you follow than what I've mentioned already. Good luck with your research.
Susan