Page 15 of the illustrated K-Line Collectors Guide covers the production notes of the Kusan FA-2 molds. I would copy the text but since it is copyright material, I'll refrain.
K-Line initial production (1987) included several mold improvements.
In 1995, additional improvements were made. When I can get to a normal keyboard, i'll expand upon the details.
I have an example of the KMT, K-line, Lionel and Williams products which I have compared. The Williams version appears to be new/different tooling and came out while K-Line was still an operating business.
On a personal note, as a K-Line collector, the ALCO FA is one of my favorites and I recently completed adding Williams ALCO sound boards to what I have.