Sorry to be so tardy in responding. We probably are related as there are few Erdelbrocks around. I visited Soast several years ago with my daughter who now lives and works in Munich. We located the property where my great grandmother lived - unfortunately the house is not around anymore. My daughter speaks german, and can tell you more if you would like to get in touch with her. Send me an e-mail at firstname.lastname@example.org
for her e-mail.