Charley

Take a page from the wind instrument makers book. Since they don't have
to be exactly the same diameter, just close, pressure clamp them between
a wooden driver in your head stock and a flat wooden fitting on your
live tail stock. Make the wooden driver and tail the diameter you want
them to end up. Now mount them individually and sand them down using 120
- 220 -320 - 400 - flannel. Bit fussy to get them each centered but,
assuming they are all concentric, shouldn't be too tough to use your
fingers as feeler gauges to get them aligned. If they're really rough on
the edges, you may want to take a very light facing pass with a tool
that's ground for aluminum or plastic. Don't hog or you'll spin the
piece against the driver and burn it.

You'll need to refinish the edges after you get them smooth. A good
quick finish is superglue and raw (not boiled) linseed oil. Slop some
linseed oil on a paper towel, put on a couple drops of superglue and
quickly wipe it on the finished edge. Instant clear hard finish. The
superglue catalyzes the linseed oil polymerization. Flute makers use it.

I'd be worried about trying to do the stack all at once. If the faces
are even slightly out of parallel, you'll end up tapering the stack or
having it lash and fly apart.

Jim