Hi Jo,
The medals seem to relate to Private 7199 / 703438 Harold Prestwich of 23rd Bn London Regiment. He's shown on their Medal Roll for the British War and Victory Medals, serving overseas with them in France / Western Front from 23/09/1916 to 12/09/1919.
It's probable that Harold trained with a different Bn or Regiment before overseas duty. Another man with a very similar numbers trained with the City of London Yeomanry from Sept 1915 before transfer to 23rd Bn and serving in France from the same date.
Is there a reason why you think there's a Manchester connection?
Welcome to the forum.
Tim