owners of m490 stereo option with Equalizer

[87m491]

Has anyone seen a schematic of the 8 pin DIN plug that runs into the EQ (for line level inputs) from the head unit? I found one on line but it lists it as a 7 pin, DOH! I am trying to plug and play with a period Blaupunkt head unit with an 8 pin DIN out plug. The Head unit has a pin out diagram and a quick connection is enough to see there are not the same. I'd guess a DIN pin out schematic from the original head unit would be almost as helpful.
thx
Mike