Some preliminary notes from the comparison of the two manuscripts. For the sources, see the previous post.
a).
The man copying rBa does not know the notations in dBa' except in two
places. This means we are dealing with an
exemplar with only the lowest strata of dBa' annotations, i.e. most of
those found in dBa' don't yet exist or are unavailable. Now I've dated
most of the annotations in dBa' after 1200 in my article published in Trading Religions, ed. Volker Rabens and Peter Wick, published by Brill. So rBa text looks
earlier than this, i.e. before 1200. It shows, however, even from just these two
indications, that rBa is later than dBa', representing a recension that
breaks off from dBa' at an early
stage.
b).
rBa is seriously redacted by a hard-nosed intellectual. That's how I
see him anyway. He wants no fluff and fancy talk, gets rid of the
honorific forms, and shows off his Sanskrit words. He also takes the
emperor down a notch, calling him rGyal po. What's the political agenda I
wonder? He will also not have the narrative as བཀའ, a word that is expunged. So some are glorifying the narrative, others are taking a harsh reductive view towards it. This is surely defined by the purpose the historical story is meant to serve.
c).
rBa knows sGam po as a current and
accepted title, and mentions it most times, unlike dBa', where it is
carefully explained and then used. I guess this shows rBa is later.
d).
Both dBa' and rBa have problems with the portion giving the account of the visit of
the monks from Khotan. The start is flawed in both. This means, to my
mind, that the manuscript source of the Li Yul story is damaged as
found: the front folio is torn and unclear, thus the slightly garbled
sentence in both. I think this is going to tell us something about the
recensions of dBa' and rBa. Maybe there are 2 copies of the original
story? Unlikely. My guess is that dBa'
and rBa already
represent two recensions, albeit at an early stages. The rBa recension
we see through the lens of a strong redaction. Our scribe of rBa will
not sanction, or does not know, the name of the text with the Khotan
story.