As I understand the protocol, the Vatican only got involved if a canon law decision was appealed. So if the bishop of Glasgow approved the annulment on first request, there would be no record of it outwith Scotland. Where the relevant bit of paper might well have fed a bonfire at the Reformation.

A canon law matter won't be in Pitcairn. The hanging of the Faas probably would be, but it's also the first place anybody researching this would look, so I wouldn't expect to find anything new there.