Hi, welcome to the forum.
1. The Crown for Germany, the National Gold Mark, a crown in a circle, is self-applied by the manufacturer or German importer of the watchcase, to designate gold items with a minimum of 585 fine, in use 1884 to Date.
2.
.XX.(?) the importer/retailer mark. Although not a perfect match check out; Wilhelm MÜLLER Schwäbisch Gmünd scince 1847 and still active see:
http://www.wilhelmmueller.de/
3. 18ct the gold fineness 750/1000 or 18k
Oel.