Take a leap of faith and use my config from reply #6. I have tried it and it works. The problem with the configs you are trying is that instead of simply seizing the #2 OBi line port, you are sending digits / tones through the port as you seize it.
Mostly the setup is ok. You just need to send nothing! That way you will get the PA dial tone.
It's getting late in my time zone - I'm hoping for good news in the next 30 mins or maybe in the morning
If it works as it does for me it is instant, so you pick up #1 OBi phone and get dial tone. The only way to prove it is PA dial tone is to dial digits and see if it works.
Edit: To give it the best chance use:
#2 OBi
Voice Services -> SP2 Service -> X_InboundCallRoute:
{li}
We can build in the security later.