There was no mention of Simonides being in England when Tischendorf arrived with the CFA in 1865, with showings in London, Oxford and Cambridge. It is very possible that they had made an arrangement, since it is quite unlikely that Tischendorf would be showing the CFA if it could be challenged in person by Simonides. In fact, considering the pristine white parchment condition of the CFA, you would expect some of the people at the meetings to be quite skeptical.
Tischendorf ducks the English trip
There is a need to go back and check Lilia's chronology and the 1889 Encyclopedia material. There are publications for sure in 1864, have to double-check if there is one in 1865. The various correspondence material in England, NYC, Australia, etc could also help here.
Actually there is evidence that Simonides was in England during Tischendorf's Feb, 2015 trip.
Die getäuschte Wissenschaft: Ein Genie betrügt Europa - Konstantinos Simonides
Simonides in England: A Forger's Progress
Pasquale Massimo Pinto
https://books.google.com/books?id=go7fDgAAQBAJ&pg=PA122 (if available online)
We do not know much about the very last months of Simonides in England and how he prepared his disappearance from the scene. The last dated document from England is a letter from Liverpool of March 31, 1865, in which he wrote about his plans to marry an English woman, named Miss Morland.49 However, in January 1866 he was already in Cairo50
Note that Pinto mentions another evidence, which places Simonides in Cairo in 1866. And an 1869 book dedication. And the 1890 death information does include the (apparently undated) report of a Vienna journalist who had met Sinaiticus in Corfu where he had talked of various matters, including the first death.
The first documented report from 1865 on is the 1867 fake death in Alexandria from leprosy. Sort of a convenient joke, since the skin of Simonides was fine in his England years.
Some of the material is in the next url about the Russians hiring Simonides. Also in the PBF page "Simonides Passes Away in 1890." It would be a good idea to set up a separate 1867 Alexadria leprosy death report page.
The second document is the Tregelles report from the missionary in St. Petersburg, Donald Owens, that Simonides was working in the Russian Historical Archives section. This would fit well with an arrangement having been made between Tischendorf and Simonides.
the Russians hire Simonides to prepare historical documents after the 1867 fake obituary
In 1889 there is the Greek Encyclopedia entry.
We also have the Medvedev Russian article translated to Italian with commentary by Canfora.
Do these offer any other actual documents or evidence from 1865-1889?
Then there is the 1890 death announcement. Generally given from Albania, and Alcibiades Simonides is the name used on one announcment. However, Canfora mentions Egypt in those years, referenced in the Richard Janko review.
Simonides passes away in 1890
This is a key question, perhaps a note to Janko or Canfora .. what is the Egypt documentation?
The Classical Review (2009)The Artemidorus Papyrus
Richard Janko review of Louis Canfora
In 1867 he faked his own death: the Times printed a report that he perished from leprosy in Alexandria on 19 October, but he was seen still alive years afterwards, both in Russia (Tregelles loc. cit.) and in Egypt, where he supposedly died in 1890 (Times, 18 October). But is there in fact reason to think that more of his work, hitherto unknown, has resurfaced?
If Simonides worked on either the Artemidorus Papyri or the Archaic Mark edition, that was likely in the 1860s. These have their own threads. Although with Archaic Mark there is some question about which edition, 1857 or 1861, from Buttmann.
And is there a direct contradiction in the death reports, Egypt and Albania?
Richard Janko, in fine notes in 2016, did write to me about how he tried to find Russian publications. I will add that below.
... there must be a huge amount of material on all this in Russia, but I had a hard time even trying to track down Simonides' alleged Russian publications, some of which clearly do exist. ... I don't recall now what I found. It was by searching the database of the Russian national library in Moscow. I know Russian, but had the greatest difficulty navigating their website and typing in what I need to with a Russian keyboard, as I learned it before computers existed.