I also like old woodworking machines and people shipping parts have the same issues. Proper packing is critical. I've seen cast iron parts wrapped in garbage bags then spray foamed around them with products like Great Stuff to keep them from moving. If you do this, provide some way of easily removing the machine from the foam.
You're basically trying to do two things. Keep the machine from moving inside the box and keep the shippers from destroying your packaging. Putting the machine in something soft like tissue or an old pillowcase can't hurt either. You don't want the packing material to rub the decals off.
Don't even bother to mark the box as "fragile" or "this end up". The people loading the trucks don't have time to read or care. Remember that old Samsonite commercial with the gorilla tossing the suitcase around? Your box will receive the same sort of attention.
Make sure the person receiving the machine is aware of the extra costs involved in packing a machine so there's no misunderstandings about the shipping bill.
Rodney