"If" you pull the feed apart, here is how to rewind the balance clock-spring. The secret is to have "something" over the spring to prevent it from jumping out as you wind it. This is a KISS make up of what clock-makers use to wind springs.
Required:
Bolt < 7/16" in diameter (the size of the quill shaft) , I used a 3/8" bicycle axle 'cause I have a bunch.
A rod to fit through a cross hole like a "C" clamp handle
4" square of 3 /4'" plywood
4 ~ 6" hose clamp capable of reducing to < 1-7/1 6" This is the diameter of the spring well.
~6" "mending plate" or ~6" long strap with holes in both ends sufficient to take a drywall or deck screw
5 ea. 1-1/14" drywall or deck screws
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Split the end of the bolt for a little over 1 /2" to capture the width of the spring.
Cross-drill the bolt ~ 2" from the split end
Drill a hole in the center of the plywood for the bolt.
Screw in 2 of the screws mid way between the hole and the board edge. These are to catch your handle.
Turn the board over and screw one end of the mending plate to just inside a corner of the plywood.
Set the hose clamp to it's maximum diameter and wind the spring by hand sufficiently to fit inside the hose clamp
Push the bolt through the plywood from the side with the single screw and, with the spring oriented to wind CCW, capture the inside of the spring.
Screw the mending plate down loosely over the hose clamp
Tighten the bolt to wind the spring. About every three winds tighten the hose clamp until the diameter is < 1-7/16"
Push the handle against one of the screws to prevent unwinding while you tighten the hose clamp.
I found friction held the outer spring fine against the hose clamp. If it slips badly, you can drill a hole for a #6 screw and use the head inside the clamp to hold the spring end. You will have to deal with unhooking it just as the last wrap is going into the spring well.
Remove the mending plate and lift off the hose clamp with the spring.
If necessary, carefully reshape the end of the spring that was held by the bolt.
Lower the quill all the way down, being careful not to jam the it against the feed pinion like I did . . .
With the spring oriented to wind CCW and the outside and of the spring set to slide into the spring well so it will engage the catch in the spring well , slip the inner end of the spring over the end of the shaft and hook it on the shaft catch.
Using the end of a flat top screwdriver, and starting from the inside, push the spring a wrap at a time from inside the hose clamp into the spring well.
If the outer end of the spring didn't catch on the well wall hook, you can disengage the inner spring end and carefully wind the spring to drag the outer end of the around till it catches then re -engage have the inner end. Caution, it's easy to bend the end of the spring.