Jacket with Collar and Lapels

How to knit the jacket with collar and lapels:
Sizes: US 4-6/8-10/12-14/16-18/20-22 – UK 8-10/12-14/16-18/20-22/24-26
Materials:
15/16/17/18/20 balls of yarn (41% wool, 41% acrylic, 18% polyamide; 51 m/50 g); knitting needles US 10.5 (UK 3); 2 snap fasteners, 32 mm in diameter.
Garter Stitch: knit all stitches in every row.
Stockinette Stitch: right-side rows knit stitches, wrong-side rows purl stitches.
Fantasy Pattern: * 2 rows in stockinette stitch, 2 rows in garter stitch *.
Repeat from the 1st to the 4th row throughout.
Gauge: 25 stitches and 20 rows = 20 x 10 cm.
Back:
Cast on 66/70/74/80/88 stitches and work in garter stitch and fantasy pattern as follows: 23/25/27/30/34 stitches fantasy pattern, 20 stitches garter stitch, 23/25/27/30/34 stitches fantasy pattern.
After 32 cm (= 64 rows) from the cast-on edge, mark the edge stitch on both sides with a marker – beginning of armholes.
Work straight.
After 54/55/56/57/58 cm (= 108/110/112/114/116 rows) from the cast-on edge, bind off for the shoulder slope on both sides in every 2nd row 1 x 5 stitches and 3 x 6 stitches/3 x 6 stitches and 1 x 7 stitches/1 x 6 stitches and 3 x 7 stitches/2 x 7 stitches and 2 x 8 stitches/2 x 8 stitches and 2 x 9 stitches.
After 58/59/60/61/62 cm (= 116/118/120/122/124 rows) from the cast-on edge, bind off the remaining 20 stitches for the neckline.
Right Front:
Cast on 43/45/47/50/54 stitches and work in garter stitch and fantasy pattern as follows: 20 stitches garter stitch and 23/25/27/30/34 stitches fantasy pattern.
After 32 cm (= 64 rows) from the cast-on edge, mark the edge stitch on the left side – beginning of the armhole.
After 41/42/43/44/45 cm (= 82/84/86/88/90 rows) from the cast-on edge, bind off the first 10 stitches and cast them on again in the next row.
After 54/55/56/57/58 cm (= 108/110/112/114/116 rows) from the cast-on edge, bind off for the shoulder slope on the left side in every 2nd row 1 x 5 stitches and 3 x 6 stitches/3 x 6 stitches and 1 x 7 stitches/1 x 6 stitches and 3 x 7 stitches/2 x 7 stitches and 2 x 8 stitches/2 x 8 stitches and 2 x 9 stitches.
Work 8 cm (= 16 rows) in garter stitch over the remaining 20 stitches and bind off all stitches.
Left Front: work symmetrically.
Sleeves:
Cast on 44/46/48/52/54 stitches and work in fantasy pattern.
Increase on both sides in every 10th row 5 x 1 stitch and after 8 rows 1 x 1 stitch/ in every 10th row 4 x 1 stitch, in every 8th row 2 x 1 stitch/ in every 10th row 3 x 1 stitch, in every 8th row 3 x 1 stitch/ in every 10th row 2 x 1 stitch, in every 8th row 4 x 1 stitch/ in every 8th row 6 x 1 stitch = 56/58/60/64/66 stitches.
After 33/32/31/30/28 cm (= 66/64/62/60/56 rows) from the cast-on edge, bind off all stitches.
Finishing:
Sew shoulder seams.
Sew sleeves into the armholes between the marked edge stitches.
Sew sleeve and side seams.
Sew the collar seam by joining the last bound-off stitches of the fronts together and working half of the seam on the right side for the fold. Then sew the collar to the neckline of the back, joining points A and B together.
Sew snap fasteners 7 cm from the lower edge on both sides of the garter stitch section to secure the overlap of the fronts, 16 cm wide.