1983 BMW 320i, looking for experts

Sorry, mistype its 1982 (i could be wrong about the model, but i got the year from the VIN number)

My father works on imported cars, BMWs and benz the most, he has acquired a BMW with two plaques that indicate customization i think, one is next to the engine compartment under the hood.

it reads

Karasserie
BAUR
Stuttgart
and a serial number

The other is inside the cab on the passenger side in the dash.

It reads

ALPINA
B. Bevenslepen KG (low rez camera i could be wrong on that)

On the right of that same plaque is

Production
exclusiver automobile

there is a serial number on this one as well.

he is restoring it, overhauling the engine and other work, he asked me to do some research on his behalf because he is not good with the internet.

We both have our speculations but i would like some input please.