I've been watching the progress of this project for a while. I think it's great that you are doing something different, not following beaten path. It is even better to see that the project is really going to be successfully finished.

About the fuel rails
With some other projects I've had also problems with leaking welded fuel rails. Sometimes fuel rail material is not very well weldable and welding can produce cracks in the material. I don't know is this your situation, but I've found soldering very helpful in these cases.

Also the long, not supported piping at the end of the fuel rails could become a fuel rail fatigue problem in the future.

Good luck, you are almost there!