The fuel dump panel is not correct.
I too only see the number 1 tank dump and to make things worse you can dump all the fuel out of that tank.
Not true!
You should only be able to dump to a standpipe level with a thousand or so pounds remaining in each tank after dump.

Fuel dumping is accomplished using the normal fuel boost pumps in each tank to push out the fuel.

Fuel Dump Checklist
All boost pumps ON.............................................Check ON
Open nozzle valves.............................................OPEN
Open dump valves..............................................OPEN
Monitor fuel balance
When fuel dump complete close dump valves........CLOSE
Close Nozzle valves............................................CLOSE
Max Dump Rate 2,300 #/min - all valves open

Since there are 4 boost pumps in the center tank vs 2 in the wing tanks, it dumps around twice as fast as the wing tanks.

The 727 fuel system is loaded like this: Each tank is equally filled until the wing tanks [1 & 3] shutoff. then the rest of the fuel load is put into the center tank. After takeoff, before 3,000 pounds are burned cross feed all engines from center tank until all tanks equal, then tank to engine. This is for structural and balance considerations. Since the wings are swept the center fuel gives the plane a forward CG. You keep fuel in the center tank equal to the wing tanks for structural reasons.

Lou