Dating brass tankards
If the hinges are on the left you have a right hand door (you would pull it open with your right hand), if the hinges are on the right you have a left hand door (you would pull it open with your left hand).Almost all the locks sold here are reversible by simply removing the lock body cover and turning the strike over.
It is also very forgiving with old houses settling as they frequently do.
Tip: You can use the latches with skeleton keyhole escutcheons if you like the look but don't need a locking function.
Just paint the door behind the key hole with black paint or remove a bit of wood.
The side with the lock body will cover any repairs but you will need to be creative with the other side for the knob, rosette and key escutcheon if your door is stained.
Actually, even if you leave the plug slightly showing these locks have a primitive feel and it will only contribute to the ongoing changes for the door.