"Stock question - was my Talen stock inherited or not."
YES.
You acquired Talen on the same day as your inheritance of PPL.
It's not clear of the progression of events here - it kind of sounds like that "another corporation" was split off from Talen - but I'm not sure, but in any case each time there's a spin off or split off or whatever you allocate your basis in the "original" company between the "original company" and the "new" company based on the relative value of your holdings in the two companies immediately after the event.
Tom Young
