|This is an Irish sweater re-claimed from extensive moth damage.
First, I washed the sweater by hand and blocked it, to reveal all the moth holes.
Using stitch markers and small lengths of yarn, I marked all of the holes needing mending.
By daylight in the morning (see true colors then), I blended two colors of yarn to get the heathery effect of the original.
To mend the holes, I used a fine-gauge crochet hook and a yarn needle. Technique was a comination of darning and crocheting, and I kept the tension light so it would stretch with the original knitting. As I finished each hole, I stretched the fabric to make sure that the mending blended in.
I then converted the pullover style to a zip-front cardigan. Using a yarn needle with contrasting yarn, I marked two lines on the front of the pullover, then cut the sweater between them. This is a Scottish/Scandinavian technique called a "steek". I then ravelled the damaged front portion back to my marked line and hand-overcast the open edge.
I then picked up stitches on each side of the front, both sides the same number of stitches. I knitted the bands in a 2X 2 rib (2 knits, 2 purls). This ribbing is eases well onto a rigid zipper tape. To bind off, I used a crochet hook slightly larger than my knitting needle.
I basted in the zipper by hand. As Elizabeth Zimmerman said, the strength is in the zipper itself, so many small gentle stitches will hold it in well. I used button and carpet thread to hand-pick the zipper into each bound-off stitch on the front, and I hand-overcast the back side of the zipper on the outer edge of the tape. This double sewing makes the zipper opening strong and it stabilizes the zipper band.
Finally, I reinforced the cuffs and bottom band with a row of double crochet.
Voila! An expensive Irish sweater, now fit for many more years of wear.