Hi guys, can I add a fresh ( I hope ) look on this matter? Of course feel free to hate'n'correct me if it already was made by someone.
Drew told stick to core of the problem. For me, it is getting to the other side of the Rift, to find something. How to find it? Go in straight line, simple as that, to the arm edge. You've created mathematical equations to find other end, but then EAFOTS came and the nebulae. Is the line still going between them? Guessing not exactly.
Rushing to catalog all EAFOTS ? Good luck. Maybe it was just simple clue where to look, then the name of the cobra added the rest. Now we can align the line properly. Sol - Nebulae - two points to make perfect line. Right through the area that we have "...to plot a way across. There are no stars for dozens of light years.". Drew said, we need to keep going. He mentioned that engineers will help. Now, arm edge, not the persei but the new arm perfectly ends where the line is going. See attached file. Bookmarks every 1000ly. There is a system with neutron star which I will examine in next 10 minutes, then I'm going as far as I can. And it wasn't the 16kly as you wrote in RR description, but over 22 kly. There are some interesting star patterns there.
I'm kinda hoping for this scenario :
1. I assume, that the rift is a rift in space, like a massive wormhole, that transports everything that will fly into it ( just imagine your fear of loosing all the exploration data after anything goes wrong

Because they're constantly whispering about looking to the sky, and watching our six, and one other clue that I forgot i think the rift is generating disturbance in the gravitational field. So we don't need exact coords, we just need fly behind it and watch our six, that is : look at our beautiful Milky Way as it will distort because of the wormhole end. Visually shoudnt be hard to find the right system then. Other side of the wormhole can lead to eg. those mysterious PSR cluster or HIP 13044 alike systems. They, attention, "haven't been mapped, so take your time". We cannot find the systems of interest on the map. Maybe it is the looking on the tapestry from the wrong side, huh?
Or maybe, at the end, some new unindentified systems will pop up in the nav tab. Checking it after every jump, just to be sure.
Reorte and Riedquat are both on same "height" of 48, so is my line of search.
A wormhole to greaveyard systems, with prooves of human bestiality or other shameful deeds could be quite good reason for govs to be shut.
What do u think, a pile of ? At least I found couple of Earthlikes and water worlds, not to mention neutron stars and black holes
http://i.imgur.com/5tb3myy.jpg