I’m getting interested in the manuscript tradition of the works of Polybius. Basically books 1-5 of his history come down to us directly. Books 6-18 are transmitted by a collection of excerpts known as the Excerpta Antiqua. Finally there are long quotations in some of the compendia of the time of Constantine Porphyrogenitus. I have just ordered a copy of Moore’s study on the mss., and will doubtless know more on Monday.
But a google search revealed that one ms. of books 1-5 is accessible at least: British Library, Additional, 11728, written in 1416. Looking at my Loeb of book 1, I can even read the Greek script (not, for me, by any means to be taken for granted).
I was interested to see that the text was divided into sections, each marked with a red capital letter. Not, I note, the same ones used in the Loeb!