How was this fuel pressure read? . . . as in what device was used to read the fuel pressure?

Fuel pressure gauge hooked up to fuel rail

Okay then, next step from my perspective would be to determine if it has an external fuel filter and change it if it hasn't been already. After that, I believe it will be most important to take it to a mechanic that understands how to troubleshoot.

Pointing at essentially [all the wires] and saying "there'* yer problem" without actually finding the problem isn't effective troubleshooting.