Second session written to BD-R disc using -Z flag of growisofs instead of -M. Can first session be made visible?

On Ubuntu Linux, I wrote files to a BD-R using growisofs, per: growisofs -Z /dev/sr0 -R -J -f -graft-points ... Then I wanted to add more files, but I was not paying enough attention, I ran growisofs with the -Z option again instead of switching to -M. Now when I mount the disc, I only see the files from the second burn. Is there something I can write again to the disc to make both sets of files visible (as if I had correctly used -M the second time)? I still have all the original source files, so I could simply burn a new disc and do it correctly - i.e. I don't need to get the data to prevent loss. I just hoped there may be a way to not waste the disc since all the data is burnt on there. Here's the dvd+rw-mediainfo query output: INQUIRY: [PIONEER ][BD-RW BDR-209D][1.31] GET [CURRENT] CONFIGURATION: Mounted Media: 41h, BD-R SRM+POW Media ID: VERBAT/IMe Current Write Speed: 12.0x4495=53940KB/s Write Speed #0: 12.0x4495=53940KB/s Write Speed #1: 10.0x4495=44950KB/s Write Speed #2: 8.0x4495=35960KB/s Write Speed #3: 6.0x4495=26970KB/s Write Speed #4: 4.0x4495=17980KB/s Write Speed #5: 2.0x4495=8990KB/s Speed Descriptor#0: 00/12088319 R@12.0x4495=53940KB/s W@12.0x4495=53940KB/s Speed Descriptor#1: 00/12088319 R@10.0x4495=44950KB/s W@10.0x4495=44950KB/s Speed Descriptor#2: 00/12088319 R@8.0x4495=35960KB/s W@8.0x4495=35960KB/s Speed Descriptor#3: 00/12088319 R@6.0x4495=26970KB/s W@6.0x4495=26970KB/s Speed Descriptor#4: 00/12088319 R@4.0x4495=17980KB/s W@4.0x4495=17980KB/s Speed Descriptor#5: 00/12088319 R@2.0x4495=8990KB/s W@2.0x4495=8990KB/s POW RESOURCES INFORMATION: Remaining Replacements:16843296 Remaining Map Entries: 0 Remaining Updates: 0 READ DISC INFORMATION: Disc status: appendable Number of Sessions: 1 State of Last Session: incomplete "Next" Track: 1 Number of Tracks: 2 READ TRACK INFORMATION[#1]: Track State: partial incremental Track Start Address: 0*2KB Free Blocks: 0*2KB Track Size: 10564928*2KB READ TRACK INFORMATION[#2]: Track State: incomplete incremental Track Start Address: 10564928*2KB Next Writable Address: 11867264*2KB Free Blocks: 221056*2KB Track Size: 1523392*2KB FABRICATED TOC: Track#1 : 14@0 Track#AA : 14@12088320 Multi-session Info: #1@0 READ CAPACITY: 12088320*2048=24756879360 The track size of read track #1 (10564928*2KB) is the correct size of the first burn; the track size minus the free blocks size (1523392*2KB - 221056*2KB) is the correct size of the second burn.