Yes, I will buy a mechanical fuel gauge!
Video from latest start:
https://youtu.be/j9eKtrIbaTo
I have used STP injector cleaner and and added another 3 gallon gas today. Think the car runs a bit better after running engine (not driving) for about 15 minutes.
As the OBD-reading shows it's also up to 400 kPa/58 psi. Can it be there is dirt and water in the lines? During engine restoration the car have stand still in garage for 1,5 years. But still no idle below 600 rpm.