The additional serials for these discs were included in the comments, however the main serials are not in the Serial field. However, I am unsure of which is the main and which is the alternate, because the Soundtrack Disc (http://redump.org/disc/44010/) lists the numeric serial, which I thought was the main serial, as the WB Games ID. The serials for all four discs and the Soundtrack Disc are listed below:
Disc 1: 9389_LAB1_EN, 5000178835
Disc 2: 9389_LAB2_EN, 5000190863
Disc 3: 9389_LAB3_EN, 5000190865
Disc 4: 9389_LAB4_EN, 5000194093
Soundtrack: 9389_ALAB_EN, 5000190880

Scans for all four game discs and the soundtrack disc are attached.