Edward VIII officer’s gilt 23mm button with royal cypher EIR

The 23mm officer’s gilt button has the royal cypher ERI [Edwardus Rex Imperator] and the backmark FIRMIN LONDON. We have only seen a very few of this pattern of button and cannot decide exactly who would have worn it. The introduction of the I  for Imperator into the cypher indicates a likelihood that it was for use in India, possibly by aides de camp but we cannot be sure. The button retains most of its original gilt finish. aug31/1

As Edward VIII reigned for such a very short and difficult period standard reference books which might have helped us were not often reprinted before the badges and buttons were succeeded by those of his brother George VI.