I've thought about making Henry a little suit jacket, but didn't want to start because it would take so long with lots of little details. By using an old suit jacket, you get some of the fun details without the time and advanced construction.
Old suit jacket
12 mos little boy suit jacket pattern
thread, pins, scissors
3 yards bias binding either 1/2" or 1/4" (I found 1/2" to be a lot easier.)
1. Lay out front pieces with fold line matching the fold line of the jacket lapel. I found it was best to go as high as possible so that you get the detail of the front chest pocket and get as little amount as dart as possible.
3. You will have two fabric fronts and two lining fronts. Separate them and cut out any extra layers to get rid of extra bulk.
4. Fold the sleeve on the under arm sleeve. Lay the pattern out on the other fold. Either line up the bottom with the hem and don't cut anything or have it above the sleeve and cut the hem off. (If you cut the hem off you will add bias binding to the edge. If you don't cut the hem off you will have a regular sleeve hem.) Also, if you want to add elbow patches, add them before sewing the sleeves in.
The sleeve fabric and lining will probably be sewn together under the buttons. Don't worry, you will still be able to work with the as if they were separate.
Put the lining inside the fabric jacket. Sew the felt collar seam allowance to the fabric collar seam allowance and push all the other seam allowances and fabric pieces away.
14. Add button and buttonhole right under the lapel fold.