15K 62.5% Gold cufflinks Birmingham 1909

Occasionally you come across a piece of 15 carat gold. It has a gold content of 625 parts per 1000 or 62.5% gold.
This WAS a British Commonwealth standard for a high carat, strongly yellow and reasonably hard gold that was used in pieces that had a lot of wear like bracelets, chains, etc but high quality gold was still required.
It was discontinued in England as a gold standard in 1932 with the Commonwealth member countries soon following.
These were my grandfather's, and were then used by my father, and now by me!