The city of Niagara Falls, Ontario has put online photos of all the stones in the cemeteries that are maintained by the city.
Here is the link to the site: http://www.niagarafalls.ca/city-hall/municipal-works/cemeter...
1. Type “Lockhart” first in the search box to see a list of all the Lockharts buried in the municipal cemeteries.
2. Click on “Details” for any of the names you wish to investigate.
3. Click on the thumbnail photo of the stone on the top right of the page to view the enlarged photo.
4. Now do the same for surname “Gould”.
You will find a John A. and wife Adrena buried in Lundy’s Lane Cemetery.
In the same cemetery there is a Roy Ivan but no Roy Malcolm.
In Fairview Cemetery you will find Pearl V. Gould and husband Everett Gould.
Note that church cemeteries are not maintained by the city and therefore are not included on this website.
I checked the newspaper index on the Niagara Falls Library site http://www.nflibrary.ca/nfplindex/start.asp?db=cari
but could only find a listing for Adrena. Her obituary appeared in the local newspaper on Friday, Dec. 27, 1991... p. 17. If Adrena married your Lockhart, then perhaps the reference librarian would email you the obit if you live at a distance. Here is the link to the contact page:https://services.nflibrary.ca/cgi-bin/contact/contactus.asp?...