Hi Richard,  First, _do not ever_ hit the end of the cylinder shaft
with a steel hammer.  The steel-on-steel contact will bulge the shaft
and ruin it.  When you need to tap the ends, use a _brass head_ hammer,
hold the cylinder in your hand and don't hit it very hard.

What you need is a can of "Kriol."  You can buy it from Nancy Fratti.
It's the best penetrating oil there is, much better than WD-40 (which
has some acidic compounds in it).

Stand the cylinder on end and make a pool of oil around the shaft on
top.  Leave it to work down into the joint for a day.  Turn it over
and do the other end.  You might want to do each end a couple times.

Then tap the end of the shaft lightly with a brass hammer while holding
the cylinder in your hand.  Then do the other end.  Go back and forth a
few times and see if it starts to move.  If it doesn't move or only
moves a little, repeat the process.

Be very careful and don't force it.  Kroil will almost always work it
loose after a couple tries.

Regards,
Craig Smith