I noticed that the frames for both machines look almost the same. But Hissatsu Shigotonin IV is Kyoraku, and Ghost in the Shell SAC is OK!! (which I know is a division of Kyoraku). Here is an image of the machines side by side:

Frame-Comparison.jpg

I have the playfield for Hissatsu Shigotonin IV, but never thought to check if it would work in the Ghost in the Shell frame. Does anyone know if the playfield is compatible with the OK frame? If so, that would mean I could play Hissatsu Shigotonin IV for the first time. (it's been in its shipping box since I imported it from Japan back in 2013 or so)