I'm not sure who your distributor is, but they will likely have to order a set in for you. Ketron Italy are excellent when it comes to spares support. I often have to order parts for customers going back to the MS series and so far they have filled every order. The SD5 is still current so shouldn't be a problem.

How come they were damaged?

go to www.ketron.it and click on Distributors and Support. If there is nothing there then use the 'Contact Us' Link