Front View
I decided to make a pattern from the original one since all the pieces are flat with very little complicated sewing involved.
I measured the existing jacket by laying it on a flat surface and measuring each element. The jacket should be loose. It can be adjusted somewhat by how tightly you tie the side ties, but freedom of movement is the object here.
Then I transferred the measurements to a diagram drawn by an old Apple program called SuperPaint. (How I loved this simple little program--sadly it doesn't work any more with new operating systems.) This would probably fit a Woman's Large size. 16-18 or 1X or a Man's LG to XLG.
I also made note of features of the jacket like the angle of the sleeves from the armpit area to the edge of the sleeve. You could put the pocket on either side and make the ties longer if you wish. Note: Most of the diagrams show one tie (two strips) on the inside and one on the outside. However, you can have 4 ties overall if you want.
One part of a pair is sewn to the inside seam on the side, the other tie goes just inside the overlapping lapel and opposite of the inside tie. They can be looped together or tied in a bow. I like to knot the ends of the ties too, just for decorative purposes.
Back View
Note that there is a facing at the back yoke. This can be one square piece, sewn inside with a French seam. This is strictly optional. If the fabric has enough body, the facing can be left out.
It gives structure to the shoulder area.
The fabric can be cut all in one piece, going over the shoulder and down to the front. (length optional) You can use the front/back piece as a pattern and cut the shoulder reinforcing after the initial front/back piece has been cut and folded out flat. See Fabric Layout illustration below.
Original Monk's Jacket measurements.
The Neck and front band is 72 inches long, 2 inches wide when doubled. It is cut 4 inches wide.
The ties are 15 inches long and cut 1 1/2 inches flat; 3/4 inches wide when folded over.
Sewing notes: Sides, back seam and under-arm seams are all French seams.
Attach the neck band all around the front, neck and to the other front. Fold over and stitch down, then stitch in rows (your choice on spacing) to reinforce.
Sides are worn left over right, covering the pocket.
Fabric Layout
The back piece is placed on the fold. The two front pieces are cut out as two separate sections and so is the sleeve, which is shown laid out flat. It could be cut as two pieces laid out on the fold.
The long front finishing band is best cut out as one long piece and the ties can be cut from left-over fabric.
Reverse the front sides and establish the neck hole. Cut a corresponding hole in the interfacing. Sew the shoulder seams; back and two front panels. A neck opening will be created and you can trim the back section in a slight curve to allow the neck band to sit well around the neck.
Shoulder under facing: A square fabric piece that forms an under the shoulder reinforcement can be added. It should be the width of the back and extend down the front of the jacket over the chest. This is an elective added element to the jacket. (see the front and back views for placement.) After the shoulder seam is sewn, add this underlining, sewing a French seam and trimming off the excess fabric.
Sew on the sleeves placing the center of the sleeve at the shoulder seam.
Fold over the jacket at the shoulder, matching the bottoms, arm hole and sleeve seam and sew together in one long seam, Clip the arm hole curve to ease. Leave a side split if desired.
Hem the sleeves and bottom. Then sew the ties by hemming the ends, folding double and stitching down. Attach by folding about 2 inches at the end and stitching them inside and at a corresponding measurement on the inside front piece. (Inside on the left side; outer right front. Inside on the right inner seam; outside on the left front.) See diagram for the front.
Sew on the neckband, attaching it all around the neck and front. Clip for ease at the sides of the neck. Fold over the band and stitch down. If desired, topstitch for reinforcement and design.
Suggestions: a contrasting band and sleeve facing can be added to create a different designed jacket. A contrasting fabric where the sleeve joins the body, the collar and front band and front ties are also areas where different fabric could be used.