Thank you! All places added to map, ref & csv.
Quite a garbled situation there on Srednoi/Srednego islets... i've done my best but a few things remain uncertain.
Starting from the certain place...
Black Rock is indeed Skaly Chernyye/Kuro Iwa (it's formed by three little islets, whence the plural in russian name). It matches with bearings, the russian and japanese name matches (those rocks are indeed black, Kuro and Chernyy are japanese and russian words for black) and i've found it mentioned here (added the pdf in our references): Notes on the Kuril Islands by Captain H.J. Snow, 1897
(page 68 of original book - page 82 of the pdf).
Srednoi rock should be indeed Skala Srednego, which is a little rock east of Skala Khitraya (Hira Iwa)... russian name matches but i'm not totally sure (skala singular, skaly plural - ostrov singular, ostrova plural - sredni/srednoi=srednego/suride).
I've not added Srednoi Island... there's no such named place, unless they're referring to Skala Khitraya (Hira Iwa) which is the bigger one (but almost always under water).
I've added, instead, Srednoi Islands
and Srednoi Rocks as aliases to Ostrova Srednego, which should be the name for the whole bunch of islets.
I've added, also, Skala Khitraya.
For Japanese names, Suride Iwa was quite puzzling.
On one of the map it seems to address the Skala Khitraya+Skala Srednego block of islets, the lettering having the same size of other Iwa in the area.
On another map the lettering was bigger, as to indicate Suride Iwa was the entire archipelago... i'm inclined to think this is the correct one. The lack of a plural form in Japanese names makes things difficult when, as in this case, it seems there's a rocky archipelago named X and an islet of the archipelago named X too. Probably "Suride Iwa" was used to indicate both the entire archipelago and
the little rock.
I've, however, left out and yet to add any Japanese name for those islets. Will do soon.
Bobushkin Rock should be Skala Babushka (47.51969, 152.79064 - 47 31 11N, 152 47 26E) west of the southern one of the two Ushishir Islands.
Simusir is the big Ostrov Simushir (46.96498, 152.0459 - 46 57 54N, 152 02 45E)... Ostrov Revuchiy is a little islet along its southeastern coast.