Firmware offsets ignored by ntktool

[domb84]

Hi all, not strictly a dash cam firmware issue but I'm modifying a film scanner that uses the same Novatek chipset. I cannot seem to retain the partition offsets when trying to repack and reassemble them. When I open and unpack the firmware I get the following:

The filenames that are extracted return the correct @offset. When I repack the partitions, both of them create the partition at 00000000:

[INSECURE] Checksum magic is (8000).
Detected raw nvt firmware image (NonComp)
checksum: f9f3
Writing at 0x0000006e
Compressing 'C:\Users\xxxxx\Documents\xxxxx\CH341\M127 ROM\CAM-M127-A1-V1.0-ROM\m127@000008f8.rbn' to 'C:\Users\xxxxx\Documents\xxxxx\CH341\M127 ROM\CAM-M127-A1-V1.0-ROM\m127@000008f8.bcl' (FullComp)...
Creating compressed portion at 00000000
Done.
startval: 0000

When these are repacked and merged the offset for partition 0 is 000000. How can I retain the offset when repacking?