Stunning vintage diamond cut cufflinks and tie bar

I believe these are European made due to the "750" hallmark, however I am unsure about the rest of the hallmarks.
Tie bar and cufflinks are all stamped with same makers marks and hallmarks.

Tie Bar (also known as tie clip and tie slide)
Diamond cut design
Tie clip also has a button link that secures on shirt button

Length: 2" (approx)
Width: 1/4" (approx)
Weight: 5.39 grams

Cufflinks
Classic square shape with a diamond cut star design in the middle

Measurements" 11/16" x 11/16"
Weight: 9.46 grams

Pieces are in excellent condition and the set weights 14.85 grams. Please use photos as a reference to the condition. If you happen to know the origin of these hallmarks, please let us know.