I've got 8 years of EM repair and restoration under my belt, but I've decided it's time to try solid state. But, I'm lost at sea on this technology. I'm looking seriously at a Williams JL ('81) with a system 7 that looks terribly intimidating. I can visually assess the machine mechanics, PF and graphics okay, but I would really appreciate a veteran system 7 guru to give a look-see at the 4 internal pics I've managed to get from the seller. It looks very clean overall, and I don't see corrosion from a cursory look, but I have no base of knowledge and could use any help I can get before I take this plunge. BG looks perfect, all game functions, displays and sound work fine, and owner says no battery damage. So it's not a project machine. I'm trying to learn everything I can before I invest in the road trip.