Hull gasket for jetpump 2004 speedster 160

[BADEN420]

Hello friends. I have a 2004 speedster 160 with the mercury m2 jetdrive. Something broke in my jet drive gear box. I found a good condition used replacement jet pump. Does anyone know what gaskets I need to swap this? I see a rectangle shaped gasket on the parts diagram but no part number. It looks like a clamshell gasket that gets siliconed to the hull? Has anyone had luck re using this gasket or know where I can get a new one? Also does anyone know what holds the jet drive in place? Is it just attached to the motor with the hull sandwiched in between? I assume that I have to remove the motor to get the pump out? Thanks for any help.