I own a copy of the UR Text.
It has never been published, it is the
unrevised manuscript and it is passed
from hand to hand.

I will point out that there is also the Thetford Edition,
which has been published and reads very differently
from the conventionally available ACIM.

One significant difference It begins with the Clarification
of Terms found in the Manual. Another difference is the
UR Text speaks of the Spiritual Eye, rather than the
Holy Spirit. One problem with the UR text is that you'd
really have to be a scholar to corelate the texts because
the order of paragraphs and placement is dramatically
different from version to version. But in many cases it's
really worth it because the earlier versions, IMHO, provide
a more open-ended, lighthearted, flexible flavor.