Michael Lindgren wrote: (clip)  Then I leave the handle in the lathe
and do a test fit.  I just put the chisel loosely on the handle and wiggle
it and rotate a bit to find where it is tigh loose.  The rust on the inside
leaves good marks on the wood where you should remove material.  When I am
close to having a snug fit I work with a file and the lathe turning
slowly(the only way mine turns in any case).  When I am happy I cut the
handle blank off, (clip)
^^^^^^^^^^^^^^
There are a few ways to fit the taper to the socket.  One way I would like
to mention is to hold the chisel in your hand, and with the wood spinning in
the lathe, press it gently onto the taper, until you see smoke.  Then take a
light cut to remove the blackened wood, and press it on for another try.  In
a few cycles, you can produce an excellent fit.

Of course, the lathe should be steam-powered, or water powered, or else it
needs to be a pole lathe.  Or, you could do what I do, and lie a little. :-)