Willison couplers

Here is a picture

As can be seen those Willison-couplers are made by ASF in the http://www.amstedrail.com/ group. However, at http://www.amstedrail.com/amstedrail/co ... s-drawbars there is only knuckle couplers shown. The Willison couplers are compatible with the SA3-coupler and now all new cars for LKAB and Northland in Sweden get ASF Willison couplers.
What is known about ASF, are couplers steel-cast in America or China?

Have received from Amsted:
"Amsted Rail does produce Willison couplers. Our web site currently does not show the various couplers we produce for use outside of North America"

I also now know the Willison couplers are cast in Mexico.