I have, on several occasions, messed up several builds. A bunch of little stupid mistakes that in the end really showed up.
My suggestion,
Take your CVA. Measure the barrel. Get a stock, probably a Lancaster style. Inlet the parts.
That is what I am doing right now, and I have a stock to use for reference. That and this forum, and other sites.
I have a 7/8ths barrel, and the stock is a real tight 7/8ths. Real tight. I got mine without a lock cut out. I will have to do as much work anyway, so I got this stock with the ramrod channel drilled, and the barrel channel inleted.
I will have to inlay everything, pending getting a replacement lock. An upgrade. I have to cut one dovetail, make three barrel pin lugs, inlay the barrel. I am right now, inletting the pipes. I also ordered a muzzle cap.
I am also changing the butt plate to a wider one.
I am glad I did this one. The rifle was a shooter. A proven base to start with. What I am learning from my inletting is priceless. Get good chisels! They really help. Each part I do, I get better and better.
I got videos by Jim Turpin. They help also.
That is my approach. I got tired of wasting good money, barrels, and locks. When I am done, I will not have a museum piece, but I know it will shoot, and I can tweak it. That is all I really wanted anyway.
I want to make me an Hawken fullstock with percussion cap upgrade. I saw one a long time ago, and it is there in my mind.
I will, actually finish this rifle though.
It is nice to have hands on the stock the parts came from.