Need help for brother on 81 380 unstored

The car has set for at least two years. Now he drained gas and put new gas in tank. We put a gallon into intake hoping to get it to start. It will run fine as long as you physically pour gas into in.
My question(s): Is the fuel distributor wasted after sitting that long? Could it be the fuel pump went out while sitting? Mice found the car in storage also. What is the probability of it being electrical to fuel pump being chewed? He (and I) are not Mercedes educated at all.
I know I drained the tank, flushed the fuel line, pump and carb on my Corvette after a two year unintended storage and it ran. However, there were severe deposits in the carb. My theory is that the same situation exists in the fuel distributor on the 380. Can an individual fix this by flushing after removal of the lines to cylinders, etc. I have read on this forum that fuel distributor is unfixable. Any ideas folks? Thank you in advance.

Appreciate the advice.

If the gas had water in it after a year Bosch pumps have trouble get new pumps. And if you like chevys that much rig a Delco pump up.