One way to establish kinship is to participate in a Surname Study.

Results for The MALLORY DNA Study participant kit #34232,
descendant of Peter Mallory b. abt. 1623 posted online 10 June 2005 indicate his DNA do not match
descendant of Roger Mallory b. abt. 1730 Prince George Co VA previously posted.

Which branch matches Mallory ancestors in England?

Male Mallorys (and surname derivatives) from are encouraged to participate.

The Surname Study is only a few months old, so you would be welcomed as its first UK participant!

Link to The MALLORY Surname DNA Study:
http://www.familytreedna.com/public/mallory/