Cap Badge help please?

[shadowwolf]

Hi all, a friend of mine recently purchased a box containing medals and medalions belonging to an officer who served in the second Boer war, The Great War, and World War 2. During the WW2 he was an officer on HMS Ajax
This cap badge is part of the collection, does any one know which regiment it is from? All I have found out so far is that the 1900-02 at the bottom refers to the Second Boer War, and that the plumes at the top are The Prince Of Wales Plumes.

[bichon]

Hi
7th/8th/9th Btns Middlesex Collar badge
cordially
Didier

[shadowwolf]

Hi
7th/8th/9th Btns Middlesex Collar badge
cordially
Didier

Thank you.