An update on Fedhill. They are in Mass where I am so I had conversation with them today, and also called AGS in MI.
The Fedhill Nicopp product was developed in Great Britain about 20 years ago. The tubing that Fedhill sells from their Oxford MA location is Made in England, and it meets ASTM and SAE standards. Fedhill does not sell made up lines, that use the tubing made in GB, only rolls through their website.
The AGS product, (American Grease Stick) is in Muskegon MI. They buy their tubing in bulk from China, and are a converter, making up lengths of flared tubing with fittings and selling rolls. The rolls are sold by NAPA, and the made up lines with fittings by Autozone and likely others. Some of this tubing is also made in India. The quality of the nickel/copper alloy and the process in China and India is likely suspect, and may or may not meet ASTM or SAE standards. Fedhill, or Federal Trading Company is a distributor for AGS products.
For fuel and brake lines, I will be buying the tubing from Fedhill that is made in GB, as it also meets British standards. Thanks to 51 Merc CT for posting the company information.