I believe this is an old thread, but maybe someone will see it!
John Wing was my 2X great-grandfather and a long-time brick wall in my family research. However, I think I have some answers.
I think it's almost certain that he was the grandson of John Wing and Elizabeth Alder, as I have 15 confirmed Ancestry DNA matches showing John and Elizabeth as common ancestors. Three of their children were married in North Moreton and raised families in that area. But William b. 1772 moved to Stokenchurch, where he married Alice Biggs in 1820, shown as a widower, and died there in 1849. The mysterious John Wing also shows up in nearby Marlow, marrying Elizabeth Holmes there in 1829.
Although we have no record of William's first marriage or John's birth, this would suggest that John moved from North Moreton with William at some point as father and son.
If this is correct, it links John to a long line of Berkshire Wings.
P.S Polomint - It seems we may be 5th cousins, sharing common ancestors John Wing and Elizabeth Alder!