Be very careful with Findagrave entries. What you want is exactly what the gravestone said, not whatever the person who made the entry surmised from family tradition or another uncited source such as a death record or obituary - which may be wrong and often not entered on the actual gravestone. A very large number of Findagrave contributors put in (right or wrong) maiden names or precise vital dates in their entries that are not on the actual gravestone.
Consider whatever the contributor put in, that differed from the actual gravestone entry, as possibly a clue to the existence of a record that you can then look for. But the contributor's assertion in itself is not evidence that what they said is true, any more than assertions in trees are factual in themselves.
In addition to errors on Findagrave entries, the actual gravestones may also be wrong - for one of my ancestors, both birth year and death year are definitely incorrect, and I have found many other actual gravestone errors, such as death date a year or more after their estate was probated or after a death-record entry that was made close to the actual event in time.
One of the Findagrave founders himself put an incorrect entry in for a gravestone (his interpretation and expansion of an actual rather long inscription).
The Ancestry.com MemberTree program does not link any burial items to actual burial event; you should not let the 'save' overwrite anything you have entered for the person. This goes for items from the Veterans' Administration cemetery entries and various War Veteran Burial database entries, as well as the ones in Findagrave.
The actual gravestone text would be part of your group of evidence for the person, and should be taken into account when you decide what to put in for vital dates - but like anything else made by humans can have mistakes.