Note that you have four scenarios to cover:
- The user tries to update the record, but someone else updated it first.
- The user tries to update the record, but someone else deleted it first.
- The user tries to delete the record, but someone else updated it first.
- The user tries to delete the record, but someone else deleted it first.
In light of this, if you need a single message try this:
Operation failed because another user has updated or deleted the record. Your changes have been lost. Please review their changes before trying again.
Even better (but more work) would be to offer several variations of the messages based on the specific conditions, and if possible to tell them who the other user was.
You should also consider the user experience.
Deleting is often done from a grid, so saying "the new values are shown below" may not be appropriate except for scenario 1 (update/update).
Also, scenario 2 (update/delete) is tricky because you probably want to redirect the user to a new form. Otherwise, if the record they want to update is deleted, what are you going to show them?
Scenario 4 (delete/delete) could arguably be ignored. Someone else beat you to it, so what?