well i got my most recent one off of an early L27, the only difference was that on the L27, it was mounted upside-down from the way it is on the LN3 and it had a different post in the back, but i just bent the old one, tightened it down and away we went.
It was a ground connection for the L27, but was easily rectifiable as i just said.
They used these on quite a few cars, there are HUGE arrays of cars with the 3800.
Also, look for any squeeking, that can be signs of a dry bearing, and then once they are dry, then the ball bearings break and then they make awful cracking sounds.
Mine was basically brand new from the 92 park avenue i got it from. it was replaced 150 miles before the car was junked.