I read somewhere that Sheffield and Solingen, for a time, swapped steels. Then as steels became more abundant in England, they would ship to Germany for other processes. Germany would ship to England for MOP and other scale material.

It is all intertwined and it would not surprise me to learn that the steel came from the same mine. So a Solingen blade would have the same steel as a Sheffield.

American steel is made here so all the razors that were made by American companies were made here.

There were exceptions. American Companies that used German blades etc then restamped then with the companies logo.

I really do not think it was so much the steel as the forging process. A good blacksmith family was worth there weight in gold if they could produce superior edged weapons. Obviously crappy steel, is just that, but even marginal steel could be made into a good shaver with the right smith at the helm.