Hi John - Great Electrical Repair Question!
John it sounds like you have lost a hot leg, this would explain why you are getting a 49 volt reading which points to a neutral feed-back. The circuit that is not working needs to be physically traced to find where the circuit is open. If you cannot find the problem then the damaged circuit will need to be capped off and terminated in junction boxes and a new replacement circuit installed but not attached to the defective portion of the original circuit. If the original circuit is part of a 3-wire set or multi-wire circuit, then careful attention must be given to the shared neutral on any of the branch circuits. John, I have repaired several homes that have been struck by lightning, many of varying degrees of damage. The worst one destroyed every electrical and electronic device in the home and actually blew the romex wiring open where the voltage to ground blew out of the romex jacket and went to ground to a gas pipe in the attic where the romex crossed the pipe