[Alan Douglas]

I can offer some experience. Make a bobbin to fit in the space. The cylindrical part can be glued-up paper, a loose fit on the iron pole piece, and the cheeks can be stiff cardboard, even cereal-box cardboard will do. But take your time and do it neatly, since you don't want the wire to snag on the cheeks while winding.

The bobbin should be installed on something slightly larger than the pole piece while winding, because the pressure of the wire will cause it to collapse slightly. If this plug is smooth you can slide the finished coil off. If it's not smooth, wind a layer of thread around it first, which you can later pull out to free the coil.

It is absolutely necessary to support the cheeks while winding, or the wire will slip down into the previous layers and wedge the bobbin apart. Metal washers work well.

Scramble winding is fine, but keep it as neat as possible.

If your wire comes on a large spool with smooth flanges, the usual method is to set the spool on the floor between your feet, on end, and take the wire off over the top flange. Feed it on to the coil through your fingers (it will not burn or anything). If it wants to tangle, try reversing the spool; if it still wants to, add a loose-fitting sleeve of urethane foam over the spool, to put a little drag on the wire. If the wire is on a small spool or one with squarish flanges you're pretty much stuck with putting it on a spindle and letting it rotate. This would be fine except you need your third hand to stop it when you stop winding.