If you do this manual edit on the patched p1 rom it should stop the extra story
at offset 0x10a7a you should see 0E6020011A603066, change it to 714E714E714E714E
However, I'm pretty positive there are going to be other issues further into the story sequence. Its getting beyond my skill set / free time to be able to track them all down. It maybe best to use the original patch and/or have someone else take a look.
Someone wanna give this a try, do the above edit and also this one to the patched p1 romat offset 0x1132c you should see 2D4A15604866, change it to 714E714E714EThis should at least fix the missing story bits at the end of the 3rd/6th stage.
At 0x1132C, I can see 2D4A1560
2A66 with your preview patched P1 rom CRC32 796DDC04 ; MD5 291181C777FC93FDA84CF6BE1F628E90.
I must have typo'd that byte, what you have is correct, replace that with the 714E714E714E.
Ok, patch done, gonna test. Thanx again.
I've done ips patches to apply to byteswapped samsho5_fe.cslot1_maincpu (8 MB P1 rom CRC32 8856D0AF).
Preview ack's 8 MB P1 rom CRC32 796DDC04 : it fixes the 1st story sequence loop after each battle and 2nd attract mode loop issue, but story cutscenes at the end of the stages 3 and 6 are missing.
Latest ack's 8 MB P1 rom CRC32 CCD0DB7A : it fixes the 1st story sequence loop after each battle and 2nd attract mode loop issue as above + adds the missing story cutscenes at the end of the stages 3 and 6.
* The only missing stuff is story cutscenes English translations when the game is set in Jap region with English language. Still in Jap region, a small bug appears in options mode if English language was set before. Edit : it seems the bug is there with all the 8 MB P1 roms, even P1 CRC32 8856D0AF.