i believe mikesr was the maker of that tool, 1 1/2 hole saw cut in half and a piece of 1 1/2 tubing welded in ,lenth depending on how many baffles you want to remove. try a search in the archives, there should be more info there .
happy drilling

Politically correct ,my a r s e. http://picasaweb.google.com/106503589568630976738/Hols201002?authkey=Gv1sRgCL68iYDR577DAQ#