Among the records of the Livonian Governor General there is a large number of very fragmentary volumes concerning Swedish-Russian relations during the second part of the 17th century (Riga, LVVA, Fond 7349, op. 2, vol. 57-102 and op. 3, vol. 15-27). While the material belonging to op. 1 roughly constitutes the material catalogued around 1900 (with the exception of the volumes kept in Tartu), the content of op. 2 and 3 are said to have been found after the Bienemann catalogue was published in 1908. To me it seems like op. 2 and 3 predominately consist of records that at some point have been taken from their original volumes in op. 1 and arranged in a new way. Considering that the records were moved during both World War I and II this would seem logical and it's also clear that the occasional document from the archive of the Dukes of Courland (LVVA, Fond 554) have erroneously be moved to fond 7349.
One of these rather strange volumes is op. 3, volume 22. It mainly contains material dating from 1661 to 1685, but starts with something much older - a copy of one of the letters from de famous correspondence between Ivan the Terrible and the Swedish King Johan III. In these letters the two rulers hurled abuse at each other, with Ivan for example suggesting that Johan's father Gustaf I had been a simple peasant and not of noble birth. To this Johan reacted by describing the careers of some of his more distinguished ancestors, explaining their high rank by comparing them to distinguished officials in France, Poland and Lithuania.
I am not sure what role such material could play in Swedish-Russian negotiations almost 100 years later, but apparently someone on the Swedish side must have felt that it would be useful to have at least one of these letters copied.