Hi Nick,
Interesting. Will you run the DumpMobiHeader.py program on all variations of these periodicals and pm them to me. Also look at the exth_flags and see if there is any info there. The DumpMobiHeader.py program should work on even encrypted ebooks since it only looks at the non-encrypted parts.
It can be found here:
https://www.mobileread.com/forums/sho...63&postcount=8
Thanks.
Kevin