I have one exactly as you describe. Tan/buff color with patch pockets, knotted leather buttons, and even has leather elbow patches. Bought it a couple years ago at a resale shop and it fits me perfectly. It's one of my favorite cool-weather jackets for wearing to the office.

I've often thought about having it converted to a kilt jacket, but I just don't think I could bear to not have it for work. Wish I could find another just like it (at the same price of $20) for conversion. It would look grand with a kilt.