The number you saw in the Mayor's Office is 516, so enter it as the four digits 0516 on the dials in Captain Ziggs' quarters atop the Hub. You can try as many times as you need to to enter them (try to stop early and let the wheels turn). The combination opens a secret room in the quarters.
you can get it on the far left of steamworks island, past the living headquarters.
There is no password, but the combination for the safe is 0516.
its in the museum on mainstreet of steamworks island :)
The combination for the painting in Ziggs' room is 0516
0516
go to the nearest fire exit andfind out the secret code(:
It's Steamworks Island #14th Island
(The solution is at the related question "How do you beat Steamworks Island")
It is at the far left past the living quarters. It is covered by vines that have to be removed.
the crab on steamworks island is next to the living quarters
You go to Steamworks and head to the museum and there is the Deogen
steamworks island