I'm installing a mortice lock in a door that's never had one before. Its an original Victorian timber front door so has seen various locks over the years. There is an existing keyhole striaght through the bare wood which is quite large and ragged and has been chipped away over the years. The lock for it was obviously mounted on the inside of the door so the key has had to continually go right through the door.
Will chiselling out the mortice in the same place as this wide keyhole weaken the whole door or should I select a totally new place for the mortice and ignore the existing keyhole?