Thanks to all who have responded
My wife and I got the forms for getting the service records though we need to get a copy of her father's (James Notman) death certificate to prove he is dead so that we can get the full service records.
As I mentioned my wife's father died in 1980 when she was only 7 years old and her mother would never speak about his WW2 times and she has now passed away a year ago still refusing to speak about it.
The POW story may not be true as stories get 'enhanced' over time LOL

We do know for a fact that he was in India in September 1945 as he got married to Mary Lisiewich who we understand to be a polish nurse (not my mother in law) but James first wife.
My wife has a step brother who she thought was an uncle as she knew him when she was a child but found out within last 7 years his true identity but she does not know where he lives or even if he is alive. She would like to make contact with him as he would probably have lots of info about their father.