How many layers on a SNES PCB?

[Niku-Sama]

the main board, how many layers on the main board.
I have a feeling its only 2 but I wanted to double check and make sure, google is failing me.

long story short I need to drill into a blank area of one but I want to make absolutely sure that theres nothing in between the layers that I might hit

[bust3dstr8]

Hold the pcb up to a bright light.

[Niku-Sama]

bottom side has a extra layer over the components, I can barely make out any traces on the bottom