Well, being the IT person I am for the last 25 years – I decided to do some hardware diagnostics.. I found out that the track ball DID register controls within the jstest – so I started by removing the keyboard and the thumb drive I had plugged into the Pi 3.. and Viola! The trackball started working in AdvMame!!!!
Solved for ADVMame, now if we can find a solution for Mame4all 😉