Water Heater Adjustment? Gas Pressure too low?

[chasrahm]

1970 International - water heating for the first time in years! Cleaned tubes and verified the thermocoupler works. I believe I properly bled the air out of the water tank (just ran the hot water at the kitchen sink until all air burped out)?
Water heater fired up and ran for about 7 minutes and then turned itself off. I turned on the hot water at the kitchen sink and in a few moments had very warm water but not too hot that I wanted to remove my hand.
It didn't last too long, maybe hot water flowed warm for 2 - 3 gallons and turned back cool. I walked back around to the heater and it had not turned itself back on. The pilot light was still burning. I turned the thermostat hotter on the heater and it still did not fire back up.
I checked the propane bottle and it was very light, i thought empty. But when I removed the bottle, it felt like it still had a small amount.

Do the water heater controls have a sensor that prevents operation if gas pressure is too low?

Is there an adjustment to the temperature sensor other than the adjustment knob?

How many gallons does this heater hold?

Many thanks,
Charles Rahm,
Dallas Texas