Most of the instrument cluster is superfluous. My 81 Vanagon has only these and it's fine:

Speedometer (which starts at 10 mph and I've managed to adjust so it's about right at 40ish but reports 70 mph when you're doing 60), odometer (5.1 digits), fuel gauge (non-linear, but consistent, the top half is a lot bigger than the bottom half, no arrow because it hadn't been invented yet). And then some lights: brake warning lamp (but the bulb is burnt out and doesn't seem replacable), high beam indicator, alternator indicator, turn signal indicator (one led for both directions!), low oil pressure indicator, and EGR indicator which really just turns on 10,000 miles after you push the button on the box under the front of the car.

Don't even need a tach, cause they put one dot on the speedo where you should shift out of first, two dots where you should shift out of second, and three dots where you should shift out of third.

The gauge lights come on when the headlights are on, so that's a subtle indicator too, I guess.

Don't really need much more than that. There was an optional clock in my model year, but mine doesn't have one.