Another thing. You are simply NOT going to be able to get brake force up to grip levels without some very harsh pads (if at all) before about 1975 and that is perfectly okay. IRL, old cars do not stop well. They just don’t. And they’re notorious for brake fade because disks didn’t get common until the 1970s.
Point is, old cars are going to make you uncomfortable about the numbers but a lot of times it doesn’t matter because that is just the way things were. I have a classic myself that has four point drum brakes and… well it stops but if you have to descend a long grade or panic stop, you are in for an experience and pretty screwed, respectively.