The Suzuki violin manufacturing and the Suzuki violin company were one company before the war. After the war, a entity created by the US and allies called GHQ (for General Headquarters) dismantled some parts of 'Imperial' Japan and some companies were closed or restructured. In Suzuki's case, the two companies separated - the Suzuki Violin Company changing to the Kiso Suzuki Violin Company and the Suzuki Violin Manufacturing Company came to be called the Nagoya Suzuki Violin Company.
Kiso Suzuki went bankrupt in 1987 and the machines and materials were sold to ESP.
Nagoya Suzuki stopped making guitars in 1989.