Yes, there truly is a difference in the old Stanleys.
I tried out a German made spoke shave back in the '80s. ...........
The major difference is in the quality of the basic iron itself.
In times past they really knew how to cast buttery smooth, fine grain gray iron.
This seems to be lost now.
Try a new cast iron skillet. Just try to season and cook with it. Even if you regrind and polish it out yourself. Just try.
Now get an old Griswold and try that.
The difference is enough that you will love the old skillet and probably use it the rest of your life.
And throw the new one directly into the garbage. You won't even want to give it to a relative you never particularly cared for.
The German and the Chinese cast iron are both horribly coarse and grainy iron.
They can never be made smooth. I have tried.
The English is better, but still not up to snuff.
That could change at any time, of course.
But so far it hasn't.
yours Scott