The study of those manuscripts that contain the text of all of the Greek Scriptures is still relatively underdeveloped. There are still plenty of questions to be asked about the Greek pandects of the 4th (Vaticanus, Sinaiticus) and 5th centuries (Alexandrinus, Ephraemi rescriptus), but also about some of the later ones.
Take minuscules Gregory-Aland (GA) 205 and what used to be called GA 205abs (for Abschrift), relabelled as GA 2886. It was thought that GA 2886 is a copy of GA 205, but I seem to know that Maurice Robinson disputes this for the gospel of John (I hope he can supply us with the correct citation). And I also find this in Alison Welsby's 2012 Birmingham dissertation later published as A Textual Study of Family 1 in the Gospel of John (Berlin; Boston: Walter de Gruyter, 2014) who says that on both textual and circumstantial grounds rather the reverse is true. [It is therefore a shame that Amy Anderson in her study of family 1 in Matthew was deceived by the consensus and only considered GA 205, but that's what happens.]
Both manuscripts were copied in the second half of the 15th century for cardinal Bessarion, who donated them to the Venice library, where they still are. GA 205 is Gr. Z. 5, and GA 2886 is Gr. Z. 6. Interestingly, when it comes to the only other part of these manuscripts for which I happen to stumble over a bit of information, the situation is different. In the introduction to 2 Esdras in the Göttingen edition, Hanhart gives an exemplar for both of these manuscripts (in the Rahlfs list GA 205 = 68; GA 2886 = 122). That in itself is quite interesting, because having the parent and the child opens up all sorts of interesting areas of study. The exemplar for Venice Bibl. Marc. Gr. 5 for the section 1 - 2 Esdras, Esther, Judith, Tobit, 1 – 3 Maccabees is another manuscript in the same library, namely Bibl. Marc. Gr. 16 (Rahlfs 731), a 13th century manuscript. For Venice Bibl. Marc. Gr. 6, for the same section, the exemplar is a different manuscript, one that is reasonably well known, namely B, Codex Vaticanus. As this copy was made before 1468, this is an interesting part of the late-mediaeval history and use of the big 4th century Vatican Bible.
Just going by what we read in the handbooks on New Testament textual criticism, one would never have sensed that the formerly anonymous 205abs had been in such close contact with one of the more famous witnesses to the Greek Bible - the latter may have been its direct parent in parts of it.
The question is of course what will happen when we compare these three whole Bibles in their totality.