Yes you can take a Pulhams bus from Moreton to Bourton On The Water and from there you can take a nice walk though the Slaughters and back to Bourton, then a bus back to Moreton.
If not you can always get a Taxi from the station to Lower Slaughter or wheree you decide to go.
I can travel from london to Moreton on the Marsh by train. Any suggested , beautiful, waterside 7 mile walks ? Is it possible to get to The Slaughters by public transport ?