New Old Loom: warping with no cross

Sectional warp beam, all wrapped up and my seat of the pants thread ordering method. I put tape sticky side up on
 the back beam and on a lease stick, combed the heck out of each section of the already warped beam
and stuck it down as close to in order as I could. then I climbed around inside the front of the loom
and pushed each little thread through a heddle in a straight draw, that is 1-2-3-4,1-2-3-4.

I received the back beam of the New Old Loom wrapped with beautiful linen warp. Unfortunately, it had been cut from the last project and wrapped for storage onto the big beam without separating the threads into two groups of every-other thread. That is called the cross, and it keeps the warp threads from tangling as you pass each thread from the back beam through its heddle and reed slot and set it up to be woven and wrap onto the front beam.

WITH a cross, you can pick up a thread and know that the next thread below it is the very next thread in line. With the warp on the beam and no cross preserved from the previous project, I have the threads in rough groups of forty or so but in each little group, who knows how I can keep the tangles out?

The interwebs know, that's who.

I know I could unwrap or cut the old warp off this beam but
A: there seems to be a lot of it and
B: I know it was warped using a rack of spools so it's probably pretty neatly done and
C: Linen isn't cheap and I love a challenge.

Heddles from the front of the loom. Temporary lease stick with sticky tape and
the combed warp threads right behind the heddles where I can grab each
thread in order and stuff it into the hole in the middle of each heddle.

I've been looking hard in all the good places on the interwebs for smart peoples' advice on how to warp when you lose the cross.  It happens to a lot of people, it seems.  Some people (a surprising number, actually) just can't face it. I am not those people. Most people who have been weaving for a while realize that a certain amount of tangle is possible to deal with if you first thread up the warp in as organized a way as possible and then raise every other thread by lifting the heddles to make a plain weave shed and sliding really long sticks called lease sticks into the 2 plain weave sheds.

Then, you just slide the sticks back, tie them to the frame and go. as the warp advances, comb the tangles behind the lease sticks ad slide them back again as far as they will go.

I scrubbed the first shaft full of little metal heddles in front and put them back on, but I decided to just give the rusty back three sets a try on this free warp.  I'm eager to get going and I've been cleaning loom parts for two weeks thanks to my stubborn work on some rusty parts that couldn't be saved at the beginning. I couldn't wait anymore, but the front ones look great and I'll get to the rest soon. Really.

That is the plan. If the amount of tangle is manageable, I will get to play on the loom with a free linen warp for a long time. If it is simply too seriously tangled for me to be able to keep pushing the snarls back toward the beam, I'll get to weave a foot and then I will HAVE to cut it all from the back and begin with a brand new warp with a properly made cross.

I can only find out by trying.