Rare, Jakob Bengel, Trombone Clasp, Art Deco Style Brooch in 725 Silver and Galalith

This Jakob Bengel brooch is circa 1930s and comprised of Galalith and 725 silver. Dimensions are 2 ¼" x ⅞". Trombone clasp is in working order. Stamp of "Fabon Fse, 725, déposé" (the latter meaning "patent") on reverse.

Bengel produced watch chains and chatelaines in Germany beginning in 1875.
The 1920s and 1930s saw inroads made into the production of costume jewelry. Bengel is noted for incorporating Art Deco, Machine Age and Bauhaus themes into his jewelry.
His factory closed in 1939 but there is a Bengel museum https://jakob-bengel.de/en/.

*****Condition: Please examine the photos carefully and do let me know if you need more as I'll be happy to oblige. The silver has surface scratches (as seen in all photos) and one deeper scratch as seen most prominently in the last photo. Also, there is some discoloration to the silver in the form of an orange patina in some areas, more than likely owing to the lower level purity of the silver (725). Again, please examine the photos closely.

Thank you to https://audrasbrooches.com/blogs/audras-brooch-lore/who-was-jakob-bengel?srsltid=AfmBOooPBc_0U5146yRq4nr1PP-EbB3yqE2RKoNUBZAEj0AOAbjyvO5x for the information on Jakob Bengel.

Thank you for looking.