Lee, those volume Parts ought to be simple MIDI volume on the MIDI channel they are on. Same for reverb, chorus, etc..

I warn you, don't get into using sys-ex for those if you can possibly avoid it! It's one thing to send a simple sys-ex code for a switch, it's another thing altogether to get it to send a variable that is moving a lot (like you messing with a slider while you play) as the entire sys-ex string needs sending for each and every new value of the slider. That's a LOT of data!

BTW, if any of the switches doubles as an edit page call up (for instance, on my G70, you briefly press the Hold button, the Hold parameter engages... but you press and HOLD the 'Hold' button, the edit page for the Hold parameter comes up), you might want to go ahead and program that switch 'off' parameter, too.