First one is only good for studs, never sen or heard of second one, personaly i would just cut the head off with a big hacksaw and replace the filter housing, should be an easy find at a breakers, same on 400/500/550/750 not sure about F2750 or 650 but filters are same so may be cept F2 is black, i should have several in my tip, sorry garage, for if you come over