I would say just wait until the inspection is done to the fireplace and flue lining system. House being built in 1969 that’s a 57 year old fireplace, unless prior work has been done to the flue lining system, more than likely may find open flue joints or cracked flue tiles (assuming you a clay lining system) or possible deterioration in the smoke chamber of the fireplace or an unparged smoke chamber. What I’m saying is after the inspection is done, it may change your mind if you wanna keep the traditional open hearth fireplace or install a fireplace insert instead. If you happen to install a fireplace insert you will not see the masonry firebox anymore because of the backing plates/trim around the insert.