Hold knob 26354 with slip joint pliers and remove snail 24496 then unscrew knob 26354 from the shaft. If you did not remove the snail first you got lucky.
Golden Heavy Body Acrylic Artist Paint #1040 carbon black or Tulip washable ebony fabric paint will patch pin holes in either the bellows or curtain with low build up. The artist paint diluted up to 50% with water painted on in 2 or 3 thin coats works best. Paint the inside of the bellows, not the outside.
The bellows are attached to the case with 1/4 inch long 18 gauge wire brads, no longer available anywhere. Bond the bellows to the case if they are removed and reinstalled/replaced.