Hey Bunsen,

I think you're on the money with it being the stock Apple 166Mhz 603e CPU (180Mhz part downclocked) from a 1400/166 - as evidenced by the link below (bottom of page):

http://www.kevinomura.com/powerbooks/powerbook1400/index.html

The four yellow tantalum capacitors have the same silk-screened names.

Still, a good price for lethargic 117Mhz machines if you downlock the multiplier to 4X (the ROM on 117 and 133Mhz machines don't detect the 166Mhz CPU unless this is done)

JB