Help looking for my Great-Grandfather

Hello,

I am looking for my Great-Grandfather. His full name has always been unknown. My Great-Grandmother only told my Grandfather that his father was an Italian prisoner of war, and after doing DNA tests, the Italian connection has been confirmed. There are hardly any close enough matches on his father’s side, the closest ones which there isn’t that many of unfortunately haven’t responded (The closest altogether is estimated to be first cousins grand-daughter to my Grandfather on MyHeritage).
A possible line of I am researching includes the surnames; Gargano, Rossini, Passari, Del Vecchio, with connections to Ruvo di Puglia, Bari, Puglia. However, these names might not be accurate. Based on my Grandfathers DNA, which includes an amount of South Italian, Greek, Albania and Aagean Island ancestry, I believe my Great-Grandfather was from South Italy.

He would have been in the local area, and the local POW camp/hostel would have been in Wincanton, Somerset, England, falling under POW camp 47. The main camp of that number was in Motcombe, Shaftesbury, Dorset, England, theres a chance he had a connection to that one as well. It's unknown when he arrived or where he arrived from, but he stayed in or around Wincanton for some years following the release of Italian POWs in 1943. It's possible he was put to work or had a connection to the local Cow and Gate factory in Wincanton, where he might have met my Great-Grandmother, who worked there. My grandfather was born in Chard, Somerset, England on February 1946, given his mother's surname, with no father listed on the birth certificate.

My Great-Grandfather would have been around in 1945, but what happened after that is unknown. He could have returned to Italy, moved elsewhere, or even stayed. There's a chance that he never knew he had a son, got into trouble, or simply moved away. Unfortunately, we don’t have any first names, definite surnames, or much more information about him at this time. My Great-Grandmother was called Lilian or Lily Sansom.

I hope someone can help,

Marc