Chris,
The original lifters had a stub protruding through the hole in the hinge. It
was center punched in three spots to keep the lifter from rotating in the
hinge. When the lifters freeze up you end up spinning the end of the lifter
in the hinge hole which stops the lifter from lifting. I have re center
punched a few before the ends broke off with success however if the end is
broken off it is not necessarily scrap. I found a couple of NOS
replacement lifters in my 59 Ambassador when I bought it a couple of years
ago. They had holes drilled and tapped in the end with screws and lock
washers fitted. I have since used them on one of my vents and the concept
worked well.
Colin