Welcome to the forum Bob,
Typically Keystone doesn't deal directly with the owner where sales/repairs are concerned - they usually suggest contacting your dealer - but it can't hurt to call Keystone & talk to them.
If your dealer isn't local, then Keystone should be able to provide the name of your closest authorized repair/service center. Although they may not sell Summerland's, they should be able to order the siding & graphics that you need.
One other suggestion would be RV salvage & surplus. The following website shows one in East Bernstadt, KY; and nearly 2 dozen in Indiana.
http://www.rverscorner.com/RV_Salvage_by_state.html
Sorry to hear about your 'incident' but hope this helps,
Terri, the Chevy co-pilot