Originally Posted by Phoenix

Anything with a group, a note or a message will remain.

It sounds as if you will lose common ancestors unless you have marked them.

The bummer is those with no trees. I have found a dozen or more that I initially rejected, subsequently putting up trees which demonstrate (at least a potential) relationship.

I have revisited all my 6-8 matches, but this would be an impossible task for anyone starting from scratch now.