It's been my experience that discs failing during the finalization process are no longer playable under any circumstance.
If these discs were successfully finalized they should be playable on any DVD player.
Unfinalized Panasonic-recorded discs should be playable on any other Panasonic DVD recorder or combo recorder (but not on Panasonic or other brand DVD players). If playable on a Panasonic combo recorder these discs may be real-time dubbed to videotape and from that videotape real-time dubbed back to a fresh DVD that may then be finalized. Or, the disc may be dubbed from a functional Panasonic DVD recorder to another DVD recorder in real time.