My general advice on finding records in a particular area is in this answer: What records are available in a particular locale?
My checklist looks like this:
- Learn what records might have been created in a particular time and place.
- Research which of those records might still exist, and which records are accessible to the public (not subject to privacy
restrictions).
- Research what repositories might hold those records.
- Research which online repositories might hold those records.
To answer a particular question, it also helps tremendously to understand what kind of record might hold the information you want to know. You might be asking the wrong research question. Asking When did Charles Ormond from Forfar die? might be an easier question to answer.
You may be able to answer that by looking at other record types besides civil registrations of death or parish records -- a record finder like the one at the FamilySearch Wiki (see Resources list) can suggest other records you can search if you have negative results from a search of civil or parish records.
Whatever locality or subject you're looking for, it helps tremendously to look for finding aids or research guides written by others who are already familiar with the place and topic.
One caution: you say the 1851 Census reports your research subject's wife as widowed. That indicates that she or someone else said that she is a widow, but the information might not be accurate -- consider the possibility that she might be a grass widow, someone who is separated from her husband, or whose husband has been away for a long period of time.
If you haven't done so already, it can help to work up a timeline of all the information you already have about your research subject, noting what sources the information comes from. This may reveal clues that you may have missed, and it helps narrow the time frame and establishes the geographical scope for your searches.
Gather information about both the locality and the types of records that were created in that time and place, paying particular attention to issues of coverage. Maps are especially valuable if you need to do a radius search of parish records.
The FamilySearch Wiki's Research Strategy article (see links at end) has an overview of ways to find records of someone's death. You may not be able to find a burial:
Church of Scotland parish registers are often missing burial records. Sometimes mortcloth dues (a fee paid for use of a funeral
cloth) were recorded instead of burials.
Do you know for sure that your subject was in the Church of Scotland? Might he be in Non-Conformist records instead? Have you searched for a burial in the non-OPR records at Scottish Indexes?
Resources:
When you are ready to widen your search, try: