thanks for writing in. From the description, it sounds to me like they might be older than that. The maker is LOCKWOOD BROS., Ltd. Sheffield, UK - ca 1849 - 1920s
"15" is the gold purity. It means it's 62.5 % gold. It was used in the British Commonwealth countries and was discontinued in 1935. A good indicator that the cufflinks are antique.
Some of these antique cufflinks are fortunate to be century-old accessories. Another distinction of these antique cufflinks is that they're really expensive pieces of jewelry.
The value is not only determined by the age of the cufflinks, but also by its finish. It's not uncommon to find, especially among the few century-old cufflinks, vintage and antique cufflinks made of gold, not to mention the designs being so lovely.
Antique & vintage cufflinks are distinguishable based on the dominant design of an era. For example, one era carries the particular design popular in that era. A good jewelry historian or collector can distinguish that.
