I know this is an old topic, but still a mystery to me what the media format might have been. I notice that K3b could handle them. If you still have the disks and have a spare moment. Would you mind putting one in K3b and use media_info on it.
You may see something like below, which with some care I copied and pasted after having increased the window suitably.
Capacity: 34:06:68 min (299.8 MiB)
Used Capacity: 34:06:68 min (299.8 MiB)
Remaining: 00:00:00 min (0 B)
ISO9660 Filesystem Info
System Id: -
Volume Id: WINDVD_SUITE
Volume Set Id: -
Publisher Id: -
Preparer Id: -
Application Id: NERO_BURNING_ROM
Volume Size: 299.8 MiB (2,048 B * 153,518 blocks = 314,404,864 B)
Type Attributes First-Last Sector Length
1 (Data/Mode1) no copy/uninterrupted 0 - 153517 153518 (34:06:68)
I was looking for something else about Device Notifier and landed here.