Just had a quick sprint through Google looking at Woodburn's in Galston and found that the John Caldwell who married Anne Woodburn was the son of William Caldwell and Elizabeth Breckenridge and not part of our known family.
"oor" John who married an Anne (surname unknown) was the son of John Caldwell and Mary Morton also of Galston. John (snr) was born at St Quivox whilst William was born at Kilwinning.