Doble researchers might like to know that there is a Doble DNA Project which is helping to sort out the various Doble lines:
http://www.familytreedna.com/public/DobleIf you can locate the right candidate for testing you might be able to solve some of these problems.
The Devon Dobles are also included in my Devon DNA Project:
http://www.familytreedna.com/public/DevonDebbie