The name of the estate, Slepow Koniec, seems elusive, though. It's probably not in Estonia, as it doesn't sound like (Germanized or Russified) Estonian at all. In Russian Слепов конец means something like End of the Blind.
It's in the St. Petersburg Governate.
Other spellings are Slepov-Konez.
Anyone who has any idea where this place might be? I got curious, but couldn't find it.
OK, so one the Russian Wikipedia definitions of конец is:
устаревшая единица территориального деления населённого пункта, охватывающая одну или несколько улиц (ремесленный конец, рыбацкий конец). Как правило, такое деление возникало в небольших посёлках и городках и позже становилось тем или иным районом.
=
an old unit of territorial division of settlements, covering one or more streets (craftsmen's end, fishermen's end). As a rule, such a division arise in small villages and towns, and later became one way or another a district.
So a division of a village or small town called "Blind End", meaning it was inhabited by blind people or was a dead end would seem possible.
There are two villages in Leningradskaya Oblast called simply Конец today, both situated southeast and east of Lake Ladoga, but it doesnt look like it's any of them.