If a commercial joystick was originally designed only for japanese joystick levers, we must adhere to that format. Trying to accomodate requests for Korean levers requires that the customer properly drill a 35mm diameter opening in their metal panel. This leads to potential inconsistencies if we produce a panel with this addition, should the customer get the size wrong or position is off.
As a result, we cannot accomodate requests to create 35mm joystick holes for commercial joysticks that use a Japanese mount.
If you are looking to use with a Korean lever with collar properties that can fit within Japanese lever mounts, we highly recommend the Crown CWL-309MJ-KMS-ST25 Joystick, which offers a low-profile collar.