Packing a CSM for shipment ... I've done this twice recently.
Start with a sock machine, a lifetime supply of bubblewrap, a roll of packing tape, a permanent marker, some little boxes for holding the little bits and a very sturdy, large cardboard box...
You'll want to immobilize the crank gear of the sock machine, at least, if you don't dismantle it entirely (I didn't, just took the yarn mast off, and the ribber).
Wrap all the pieces in bubblewrap, tape and label them (labelling is optional, but it was fun). Wrap the heavy pieces in bubblewrap twice.
If you have any sheet styrofoam, line the box with that; if not, consider an extra layer of cardboard at least. Make sure the box is a very sturdy box, too.
I put little things (buckles, needles in their tins, that sort of thing) into a small, lightweight box and put that inside the big box.
My boxes ended up weighing about 30-40 pounds, I think. Parcel post shipping wasn't horrendous, well under $100, WA->TX, even with insurance.
It was a bit of a jigsaw puzzle to fit all the pieces (the big AK shown here went in two boxes, in the end). I stuffed more bubblewrap and styrofoam blocks around it all. Sure made a dent in my bubblewrap, but it was worth it to see the box make it to the purchaser in one piece!