My experience is with a 1994 PA but probably applies here:
The lower motor will normally retract the latch when you close the trunk lid. Then it should retract and pull the lid down. You should be able to make the motor retract by flipping the switch on the trunk lid in front of the latch (this switch also turns off the trunk light). This switch will be pressed up when the lid is lowered. I suspect that this is what should be connected to the 2-wire connector you describe. Does your trunk light work? I have posted a photo of this switch in the General Automotive Photographs section titled "trunk lid lamp switch '94 Buick PA".
The lid on my 1994 PA would not retract and I took the lower switch (like the one that your friend sent) apart (I had to drill out 4 rivets) and cleaned the contacts. When reassembled (I used sheet metal screws to repace the small rivets) it now works but I will order a replacement as soon as I can.