can you recline the drivers seat in a ’82 300D?

Isn't it just turning the round knobs on the bottom off the seatback?

Kinda - the big round knob on the left side of the seatback actually, located toward the bottom. Additionally, the height of the seat cushion is adjustable on these, using the lever at the left of the seat cushion. (right side on the passenger seat) Forward and back is the lever under the front of the seat cushion. The headrest is adjustable vertically by grabbing and tugging upward, and I have a friend that swears that the tilt on the headrests is adjustable but I'm not sure about that - mine doesn't seem to be. That's all I know about seats.

Conrad

The headrest should tilt forward or backward. Just grab both sides from the rear seat and twist it either forward or backward. If that hasn't been done in a while it might feel like it's permanently stuck. Just apply a little more muscle.