I don't think this is the kind of advice you were looking for, but it is difficult to advise on the structual matters from the distance of the internet without more details. The inspector's findings are certainly material to the purchase of the house. Since you are in the process of buying the house, why not make the structural repair (or at least the detailed assessment and repair estimate) a pre-condition of the sale. Structural repairs in a building that age and construction is going to be a specailized matter. You should have cost estimates for repair before closing the sale. If the costs are significant, you may want to take that into consideration for the transaction price or walk away from the deal. It up to you. If you haven't closed the deal, you can always walk away, and should if you find the cost of repairs is out of line with your agreed purchase price and what the property is worth.