Thanks for the comments Ronjoy.
The most recent work has been replacing the fuel sending unit. I had an odd problem where when I first started the car the fuel level reading was good, but then it shortly dropped to empty with the warning light flashing. If I turned the car off and back on again, it would read normally for a moment, then drop again.
I pulled the pump and sender out of an '01 parts car gas tank. You access to the top of the tank by removing the battery and battery tray. Here's the whole DIY on PelicanParts:
https://www.pelicanparts.com/techarticles/Boxster_Tech/22-FUEL-Fuel_Pump/22-FUEL-Fuel_Pump.htm
The pump was easy to remove with a slight twist from the empty gas tank of the parts car, but Red was full. I decided to leave the pump and just swap out the sender. To separate it from the pump, I just had to pop two hoses off and one wire connector. The hoses and wires extended above the tank. Installation was simple without having to reach down inside.
Here's the old sender and the top of the gas tank before I reinstalled the battery tray.
