Mommsen's False Trail?

Some time ago I posted about the F recension of the Liber Genealogus and the possibility that it might either have originated in Oviedo, Spain or that the lost library of the Cathedral of Oviedo might have been a bottleneck through which both existing versions of the F recension (one in Florence, one in the Escorial library in Madrid) could have passed.

Theodor Mommsen offered a hint there might be a third codex in Madrid, a 16th-century paper manuscript seen by Knust, which contains the so-called Corpus Pelagianum. In his MGH volume on chronicles, Mommsen quoted the old call number for the item, T.10. Through the kind assistance of Professor Jose Carlos Martín of Salamanca, I learn that this item is now shelved as MSS/7089.

To see the bibliographic record in the National Library of Spain manuscript catalog, do a call number search entering the search term "MSS/7089". The OPAC result refers the reader to the printed catalog (PDF cat) which shows that the codex contains a 112-folio copy of the Corpus Pelagianum. The cataloger considers it to be a copy of MSS/1513 (PDF cat) in the same library, which contains 28 items, none of them, as far as I can see from their descriptions, being the Liber Genealogus.

It seems to me that Mommsen laid a false trail here, mentioning Knust only because Knust had vaguely noted that there were genealogies in this codex. I have not checked this further, but suspect that T.10 does not contain the Liber Genealogus. It seems likely that of half a dozen codices with the Corpus Pelagianum, only the Escorial codex contains this book.