What are these sonus fabers worth?

List them on ebay with full disclosure and find out.

Original cost of Concertino was about $1000 plus something like $300 for stands. There is currently a pair with stands for sale here for $800.

SF importer Sumiko can be strict about not selling replacement parts unless you can prove they were purchased from an authorized US dealer. If you cannot, there is a good chance that original drivers will not be available. If you really want to sell them I would check with Sumiko first on the cost of new drivers and if they will provide them. If one tweeter and one mid need replacing, you really should replace them in both speakers, although with damage to the cabinet it might not be worth it. Depends on the damage.