Identification appreciated

[kingsley]

A couple of weeks ago one of these badges was sold on Ebay and described as British but I don 't think so. Is it? Perhaps Australian, Canadian, Sth African or NZ?
The term 'Army Reserve' was used pre-WW2 for Australian retired officers, but is now used to describe our part time militia forces. I always thought that the pre-war officers wore a large cursive letter R on their caps and a smaller block letter R on the collar with a block letter epaulette RESERVE title. One of the smaller R badges is currently on Ebay.
Any info or documentation appreciated.