First out of this tiny MacBook base is an SD reader, blocking access to the I/O board.

Well, that and a nest of cables.

At last the board is free. Here's what it's packing:

Freescale SC667334DC (maybe a custom microcontroller)

Realtek RTS5314 SD card reader controller

Winbond W25X40CLIG serial flash memory

Genesys Logic GL3520 USB 3.1 hub controller

Texas Instruments TPS75105 LED driver