Bob the Jackson lives at my house. While I cannot speak to current production standards, my now 20 year old Jacson still mskes me smile every time I ride it. Not all is prefect; it was purchased at a time when a 25c was big so while I can fit a 28 on the front, the brake bridge prevents the use of anything bigger than a 25. So your thought of the Audax sound like a good pick as far as geometry is concerned. Bulid of the Jackson was easy, Threads were clean and Bb faced well. And 20 years later, paint still looks good.
So I'd buy another one. That is, If I did not live in the PNW, which I didn't at the time Bob came into my life. What I like about C and V is that it keeps alive a time when bikes were on a personal scale and not the end product of a supply chain. So talk to your local builders first. Give them a shot. Then if you still can't find something you like, then buy the Jackson.