Okay, for those interested here is the latest...

Removed the interior panel, etc... the problem looks like two areas of a plastic part where cable/pulley is attached at the top to regulator. These plastic parts have broken off and cable is not pulled tight enough, etc...

Soooo, it looks like you're right...regulator. Unless of course it is possible to replace this plastic/metal pulley assembly by itself, but I seriously doubt it.

Is anyone aware of any diagram/service manual type documentation there might be available online for this repair? I'm sure I could figure it out okay, just like having something to stare at in case I get lost.

Hopefully I will remember exactly how to put everything back together after I get replacement parts.