Les, I would be interested in knowing what the letter in the circle just above the date code reads, I have tried enlarging. Mine is a N for Nashville. I have only seen the M05 on two 66 Shelby's and was wondering if it is SJ related only? The other FM codes don't seem to relate to any certain assy plant. My research tells me that the middle character is a zero and not an "O". Mike at PS Glass was going to check with Bob Perkins to see what he knew about FM-M05.
Ray