I don't know about binoculars but some top lenses are currently made in Germany and England.
Glass material can come from various sources.
I don't know who makes castings.
Meopta may make their own binoculars.
I doubt that any one company nowadays makes every part including mining the metals and glass.
Barr and Stroud probably made every part of their military binoculars including the best Scottish sand, which actually wasn't very good.
Ross also used British sand.
Thorium glass may have used sands coming from India.
Uranium glass filters I don't know the source. These were used on military lenses. Some filters are large.
Apparently, the sand around Wetzlar was very good for optics and probably helped the local optical industry.
Glass material can come from various sources.
I don't know who makes castings.
Meopta may make their own binoculars.
I doubt that any one company nowadays makes every part including mining the metals and glass.
Barr and Stroud probably made every part of their military binoculars including the best Scottish sand, which actually wasn't very good.
Ross also used British sand.
Thorium glass may have used sands coming from India.
Uranium glass filters I don't know the source. These were used on military lenses. Some filters are large.
Apparently, the sand around Wetzlar was very good for optics and probably helped the local optical industry.