I know this is a long time after your comment, but...

Look at the second image of step 6 on the top right of the logic board, above the unused antenna socket, there is a spring contact to the case. The connector is probably for pre-assembly testing, I'm sure they wouldn't want to use all that glue to seal in a non-working logic board to then worthless $99 / £79 / €119 device; waste of glue for starters ;-).

I don't see an identity crisis for this battery, the Thailand and Japan text are next to mandatory regulatory marks for batteries in those countries (circled diamond logo and circled PSE logo). Between them is a UL recognised component mark (c reversed UR US mark). Presumable it is less trouble for Apple to apply for them through local subsidiaries.