A heptagonal brass dish by Alexander Ritchie, circa 1910.

I’m very grateful to the Alexander Ritchie tribute website for providing a great resource. A very similar brass dish, albeit hexagonal, is shown under the brassware section. It states that this design was definitely by the Iona School and likely by Alexander Ritchie himself. The repousse foliate pattern is taken from early Iona stone carvings.

http://www.alexander-ritchie.co.uk/brass4.htm