I haven't had any experience contacting cemeteries either.
Our Lady of Mercy has a couple of contacts listed for lookups on the Canada GenWeb Cemetery Project. They don't have "underlined direct links" so you will have to "copy and paste" into your email.
http://geneofun.on.ca/cems/ON/ONLAM11869/YHoly Sepulchre page directs viewers to Hamilton branch of Genealogical Society
http://www.haltonpeel.ogs.on.ca/h/ne25.htm Hamilton branch does have a "Contact Us" option on top menu.
http://www.ogs.on.ca/hamilton/publication.phpHope you find your answer.