Thanks to Neil DuPreez... good friend and strong swimmer who coaches Ann Marie, his national standard 10 year old daughter.
He suggested I do timed 100 metres as part of my routine, allowing a set recovery each time. Did this earlier today and felt the benefits.
Swam Monday morning and Tuesday morning, doing 1200 metres each session.
This morning (Weds) swam 1600 metres comprising 300 m warm up, 10 x 100 m within 2'30" (including recovery) and 300 m warm down.
Still struggling to see how I can decrease my stroke count though. I guess it will come.