That looks like you are doing a great job of things-- let me offer a bit of advice, it I may. When you have finished the jacket, take it you a local alteration shop/tailor and have them take in the waist just a tad, so that the jacket has a wee bit of flair as falls over the top of your kilt.

You want to do this because most American jackets (tuxedos, suit coats, sports coats, etc.) are cut boxier than kilt jackets and therefore when converted never hang quite as well as they should.

This same "boxiness" occurs in most of the less expensive (read cheap) off the peg Highland jackets as well, and they greatly benefit from a bit of shaping at the waist.