If you had gone a bit longer, it may have been easier.
Most jackets of that style come to the end of the stitching on the fell (back of the kilt).

It looks like you adapted the length of the waistcoat I made, so the length is my fault. Though, I REALLY LIKE the look. I may so a "short rounded cut-off" with one of my Goodwill buys.

(The reason I squared off the ends of mine was so that I would button it closed and not need the belt)