EDIT I have Slot 21 offset for P2 now see bottom
I don't have Slots 21-40, sorry.
For the first 20 slots, you can figure out 2-20 as long as you have the code for slot 1. So the Player 2 offset for Slot 1 is AC4DFA90, it goes like this (XXXX = item code)
Slot 1
04100000 AC4DFA90 0000XXXX
04100000 AC4DFA94 00000000
Slot 2
04100000 AC4DFA98 0000XXXX
04100000 AC4DFA9C 00000000
Slot 3
04100000 AC4DFAA0 0000XXXX
04100000 AC4DFAA4 00000000
Etc.
Basically the offsets (the 8 characters in the middle) are going up by 4 every line. If you're unfamiliar with hexadecimal, just Google a hexadecimal calculator
For whatever reason Slot 21 doesn't follow that pattern, but if anybody has the slot 21 offset for Player 2 we can figure out 22-40. Let me know if you have questions.
EDIT: I was able to figure out the Slot 21 offset for Player 2, it is AC4DF9D8. Hope this helps somebody
independently verified via noexes