Thanks for reaching out Chris, I am so glad you found us!
This mark is very unusual. If the metal is silver in colour, it could be a worn 925 mark. (92.5% pure silver)
The 935 mark is a European/Continental silver mark (93.5% pure), and your "933" marking doesn’t fall into either one of these two categories. Another possibility is 933 could be a design or inventory number.
