If it had no venting and was sealed tight it would not have lasted 116
years, The beams would have rotted away there would be mold on the deck
and beams, there is air movement somehow, whether by the sheeting being
loose or planks used for roof decking air is moving through. Will there
be new sheeting, what is there now. You might change something if new
sheeting is used requiring more venting. Or the construction has so many
air leaks in the attic it just vents. Get more bids, a paid inspector
should go over everything with you.