E30 Zone

Hopefully an easy one, my key doesn't work in my drivers door, and only just works in the passengers (and ignition, boot, glove box)

I've taken the locks apart to check the tumbler codes, but they're different.

Am I correct in thinking I need to recode the drivers door to match the passengers? And the extra 4 tumblers on the drivers door are just for the deadbolt?

Correct on all points. BMW can supply a lock rebuild kit for a few pounds, which has a full selection of tumblers, and also comes with the L shaped alloy piece on the back end of the driver's lock. This part is frequently found to be worn, and is only available as part of the kit.
The cheapskate method to make your cars correct key work in the driver's lock, is to take the barrel out, insert the key you want to use, and then file off all the projecting ends of the tumblers.