Pulleyblank Great Grandfather

I have taken many DNA tests and with the expert help from a well known DNA specialist have narrowed my great grandfather to one of 4 brothers, My grandfather - James Polyblank Wood was born illegitimately in the Kingsbridge (Devon) Union workhouse on 15th July 1870.

The four brothers are:

William Pulleyblank b. 2nd March 1834, North Huish, Devon

George Pulleyblank b. 30th October 1836, North Huish, Devon

James Pulleyblank b. 31st December 1839, North Huish, Devon

Edwin Pulleyblank b. 27th march 1849, North Huish, Devon.

The surnames are sometimes shown as Polyblank or Pulliblank.

I am looking for DNA matches from any of the brother's descendants to try and find which one is my great grandfather.