Congratulations on your new house!
Have you tried turning it on, by setting the timer past 15 minutes with the heat selector set to "HEAT" to see what happens? The timer pointer is way beyond where it needs to be. Turn the timer dial to the left to set the timer to off and then turn the dial to set it at about 20 minues after you plug it in. The spring wound timers have to be set beyond 15 minutes for the burner to light. You will hear the spark ignition mechanism making noise to light the burner is there is electric ignition. I ask about this because it looks like the pilot light mechanism outside the burner area is missing and might have been replaced with an electric igniter, but I am not sure from the photos (my shortcoming, not yours) and you were only told to open the gas valve, not light the pilot. The absence of rust and fuel grime under that cover would also indicate the absence of a pilot. It would be a retrofit, but given California's energy conservation programs, it might have been done since a constantly burning pilot consumes enough gas to dry several loads a month. Did you check for a gas valve behind the dryer? Check to see if that needs to be turned on.
The pilot, if it is still there, should be at the back of the opening where you see the tubes going into the burner chamber. There should be a little swinging cover over a round hole. There should be something you push to override the pilot thermocouple, on ours it was a red button, but I don't see it on yours. You push the little swinging cover aside and hold the lighted match inside while pushing down on the override button. You should see the pilot light and the little pilot flame will begin to heat the safety thermocouple which will be visible at the top of the flame. You have to keep holding the button down for close to two minutes, but you can extinguish the match as soon as the pilot lights. Are you sure no booklet of instructions was left somewhere near the dryer? Was the dryer said to be in working condition?
I believe that your dryer, like my parent's dryer has a cast iron, drilled port burner that runs the width of the drum at the back of the dryer. There is a 21" fan that blows over the burner and into the drum. I don't know the maintenance that has been performed on that dryer, but the burners can become partially clogged with lint over the decades.
