Upgrading? Out with the old[er], in with the ”new”?
I'm glad to read that you are working on it, though. It isn't just parked.
If you have the seats out, you might as well replace the headliner, and the carpet. It's a prime time to treat and coat the floor. The seat tracks could probably use a bit of attention. Then there's the back wall.
While you have everything apart, you can dip and paint the metal brackets for the AUX and below it. Heck, you can do the same with the console skeleton.
I usually dig all that stuff out that fell under the cigarette trays. It's easier to replace the heater core and clean the box, too.
