Barbara
There is no mention of Blackadder in the book - they would have been in Edrom or Chirnside at the time. Here is the only info that I've been able to extract:
Bunkle inscriptions - Here lyes the body of John Aitken, indueller [ indweller] in Lintlau [Lintlaw], who died the 18 of June 1776, aged 63 years.
[on the other side] Also the body of John Aitken, son to John Aitken, wright in Ovenden, who died the 9 of October 1775.
There is no other mention of Aitken - they do no appear in the Session record, marriage or baptisms.
Betty