If you google Sergeant Brazier there is this
HERE..
Looking at the unit's history there is this"
3rd (Reserve) Battalion
04.08.1914 Stationed at Oxford and then moved to Portsmouth.
Oct 1917 Moved to Dover until the end of the war."
So there is/was a presence in Portsmouth... This is the link, you'll need to scroll down to see that in quotes..
HERE
Geoff