I don't know how to get back before Thomas Mead and Rebecca. There were people named Mead in Wing back to 1500, as well as in nearby parishes such as Stewkley and Soulbury. But there is a gap in the christening records:
1632 William Meade son of John and Margaret
1633 Thomas Meade son of John and Margaret
1636 Benatt Mead son of John and Margaret
1638 Elizabeth Mead daughter of John and Margaret
1640 Susanna Meade daughter of John and Margaret
1673 Anne Mead daughter of Thomas and Dorothy
And then nothing until 1719. There were, however, people named Mead living in Wing then, as shown in these entries from wills:
May 13 1690 William MEAD of Wing. Beneficiary of Mary BEAKE (DA /WE 42/03)
Dec 26 1715 John MEADE of Crofton, Wing. Cousin & beneficiary of Sarah PEELE (DA/WE 54/118)
Sep 26 1715 Thomas MEADE of Crofton, Wing. Cousin of Sarah PEELE (DA/WE 54/118)
Oct 22 1728 Richard MEAD of Burcott, Wing. Son in law & beneficiary of Samuel HOLT (DA/WF 80/38)
Sep 17 1733 William MEAD of Ascott, Wing. Tenant of Elizabeth REDMAN (DA/WF 82/172)
May 30 1739 Joseph MEAD of Cotslow, Wing. Witness of John ANSTEE (DA/WF 82/195)
(These are from a database made by a man named Shrimpton.)
Any of these might be the father of Thomas Mead the husband of Rebecca, but I don't have enough evidence.