Did you just get this car and none of the gauges work, or, did the gauges suddenly stop?
You really need to get hold of the FSM (Factory Service Manual). Once you have it, refer to diagrams BE-46, BE-47, BE-48. You'll discover that the fuel/ amp and the oil/water gauges are serviced by the same fuse as the the tach (10 amp fuse, third down on left hand side). If the tach and amp is working but the fuel, water, oil aren't I'd guess that you have some other problem besides fuses. Incidentally, the clock is serviced by the sixth fuse down on the left hand side.
Do the simple stuff first... 1) clean the body ground located in the engine compartment. It is located just above the front frame rail on the passenger side. 2) Use an ohm meter and make sure you have good fuses. 3)Check the connectors that service the instruments and clean them up, it could be simple corrosion that is causing the problem. Check connector c-3 (black), c-4 (brown), and c-5 (green). You'll find them in that mess of wiring behind the glove box. It isn't as bad as it looks. 4) run a wire through the cowl drain just to make sure it isn't clogged up and that water isn't getting through the firewall giving you electrical problems.
If that doesn't do the trick you may need to start checking the fuel sending unit, the oil pressure sending unit, and water temp. thermal transmitter.
The clock? if the fuse is good then I don't have a clue.