I inspected a 1901 house today, and I noted there was a lack of flashing above doors and windows. I am curious however, as to this particular situation. in the pictures provided you may be able to see that the windows and doors are installed under a little roof overhang, or with the siding creating a “flashing” above the windows. My initial reaction is “this may have been correct at the time of construction, but I recommend installation of flashing to protect the wood.”
Just a little unsure due to the age and particular construction.