OK, I got it. The pivot point can be different on each end, but it's the same in the rocker as it is in the frame for each end. That way the edge of the rocker and frame stay almost parallel.

That's not a CNC machine
This...

is a CNC machine.
Even if that CNC router was big enough to do the body, how far to you want to move away from hand crafted toward automated production? Wouldn't that make it work instead of fun?
You go out to the
garage shop with the intention of doing something and it doesn't come out exactly how you intended, but each time it gets closer and you're getting better, you're developing skills which is very satisfying. It's a hobby not a job.