After trying to get to a thrift store for several weeks with no success, I pulled the trigger last night and bought the grey herringbone blazer from old navy. The price has been reduced from $49 to $29. It may go even cheaper after christmas but I didn't want to risk them running out as many stores near me are out of stock already.

I had the evening to myself so I spent it removing the pockets from the coat and then pinning the bottom and trying to simulate the cut back for the sporran. Started to post pictures but it was around 1:30 AM when I decided to stop. The shape looks pretty good but needs to be fine tuned and the pins make the fabric pucker so it's hard to see the smooth tailored look during the construction. I think the jacket will work well as there is a lot of space between the top button and the lower button to allow you to gently slope the cut back without hitting the button hole.

Normally I wear a 44R which would have been the Large size but after trying it on I opted for the Extra Large to allow extra fabric and comfort.

I rolled the bottom up about 4 -5 inches and the sleeves are rolled about 2". I'm not sure if I'll have material to make gauntlet cuffs but I will be able to make the pocket flaps.