I've bought some old wooden molding planes during the past year, and
before wrecking them I have a question: there is a metal depth stop
that runs through the body to the sole. These seem totally stuck on all
my planes. Is this metal depth stop meant to be adjustable at all? The
irons themselves are adjustable for depth, but these depth stops (I am
assuming they are depth stops) just don't budge at all. Any
suggestions?

Kevin in Massachusetts