Hi Darius,
with the platforms on mast you are right, my silly mistake because I head previously outfit in head as visible on your shown photo with destroyed aft turret.
About turret roof, clearly after Battle of Yellow Sea when this turret was destroyed with 2 hits. You are right, the turret roof is here away, but i'm not sure if it was made for repair and barrel change or if it was due to destruction of turret.
Finally ... the 47mm guns:
If the red one are really 47mm 3pdr guns, well, then they must have replaced 76mm 12pdr guns. As you know, she had 20 of these guns - 12 x in midship (6 on each side) and on each bridge 4 - and the position of the red ones on the drawing are clearly positions of 76mm on bridge sections. This causes now some questions about Darius.
As far as I know, Mikasa was hit 20-30 times during Battle of Yellow Sea and beside the knocked out aft turret out of this, as well hits on funnels (I guess from 6 or 8inch guns caused) and the several times hit masts which disabled radio, she was of course hit on other places. But no where I read something about hits on bridges, particularly not on front bridge with Admiral Togo in place on top / roof of and around pilot house. So why should the stronger 76mm guns there, being replaced by 47mm 3pdr guns after battle of yellow sea? A possible answer could be that some midship 76mm guns were destroyed and would be replaced by these from bridge sections ...
But then we have now the point with the 2.5pdr and 3pdr 47mm guns, where every source tells that 6 of each were on board. The position of the light 6 x 2.5pdr guns are now totally clear thanks to the drawing, but drawing shows only 4 x 3pdr guns. Where are the 2 other one, when mast platforms where they were in origin are for Tsushima away? Maybe they replaced further 76mm guns in midship section? I see no other place left where they could be installed ... and that these 2 further 47mm 3pdr were installed somewhere is on the other hand sure.
But this all makes again the everywhere named total number of 20 x 76mm gun itself doubtful, because when they were in parts replaced with 47mm 3pdr, where are all the 20 x 76mm installed then ? Issue is really strange and makes more questions as answers ...
