Complex sentence: Facsimile editions of the theretofore out-of-print 1924 "Observations" became available in 2002; since then there has been no critical consensus about which versions are authoritative.
Split into simpler sentences: Facsimile editions of the theretofore out-of-print 1924 "Observations" became available in 2002. Since that time there has been no critical consensus about which versions are authoritative.