I get your point, Bob, and agree only partially. The pros back then didn't have many special precision tools but managed to make them handle.
The trick is knowing where poor tolerances will and won't hurt performance.
Example; I doubt having an inline motor cocked to one side a little would make any noticeable difference.
Mike Steube, in his retro building video, points out some of his best retro handlers had flaws, therefore didn't insist everything be exact.
Of course there are things that HAVE to be perfect - low CG, strong solder joints, amount and location of flex, etc.
Things like a downward tilted flag or parts binding are just a couple examples of instant handling killers.
I think that's what my old and gray buddy refers to.
I spend lots of time getting these things perfect because I have the time and I enjoy it.
By the time one of my cars gets tested, I pretty much know it's going to handle - the benefit of precision.
Back in the day, the pros could build one in a matter of hours.
Even today with all my special tools, if you told me I had a night to build one, I couldn't.
It would take a lot more than a six pack of Pepsi and a pizza for sure
Enough talk - where did I put those doggone .062 axle keepers ?