I am a fan of copper-nickel brake line after using it on two frame off restorations ('37 and '50) along with a couple lines on the '42. After I found out that NAPA had it I bought a 25 foot roll of 1/4 inch line from them. It seemed to have a thinner wall than what is sold by Fed Hill so I called Fed Hill and they sent me one of their rolls for free in exchange for sending them the one I got from NAPA. Weighing both rolls I found the NAPA roll was 40% lighter.

Now, I have no idea whether this affects the usefulness, safety, bursting pressure or anything else. The Fed Hill Cunifer is more costly than the product from NAPA but I don't remember how much. I do remember it was about 3 times the cost of ordinary steel brake line but for the low volume of my work I am fine with that.
Kent

1937 Chevy 1/2 ton
1942 Chevy 1/2 ton
1947 Diamond T Model 509
1951 Chevy 1/2 ton
1950 Chevy COE Model 5700 ~ "Barney" ~ And more pix