This is the only Spain named in Durham Records Online's records for Sunderland of this generation. He is named as the father of William Spain, baptised in 1770, and he is a likely candiate to be the father of Thomas, born 1772-73.

Carpenter at the time of William's baptism and at his own death.

Durham Records Online:
Burials, Sunderland District - Record Number: 391435.2
Location: Monkwearmouth
Church: St. Peter
Denomination: Anglican
20 Sep 1787 Thomas Spain, of Monkwearmouth Shore, carpenter.

My 5 x great grandfather.