let me see if I can consolidate these contributions for you:
Seehalde is the proper name of a location, mostly restaurants, clinics and hotels commonly in the vicinity of Lake Constance, Bavaria. If it's a brass button it could originate from a uniform, say, a doorman's greatcoat? "Gott walte" (noun, verb) means "God preside".
Using a little artistic license (by leaving out the space between "Gott" and "walte") the author has created a rhyming Motto, meaning "God preside (over) Seehalde".