I think I know where this is now.
I now reckon it is 'Canada Dock Station' on the left hand side.
There were actually two next to each other on that side, the LNWR 'Canada Dock' and the L&Y 'Bankfield & Canada Dock' station slightly further along, both primarily for goods traffic. You can make out the tail end of LNWR ie 'estern Railway' on the hoarding on the wall at the left.
The LOHR also had a Canada Dock station almost opposite these, which I now think is where the photograph was taken from.
So this would be Regent Road.
It also wouldn't make sense for Carbonari to trek to a signal box as I first thought, he would need a permit, but he could go up and walk to the end of the platform.
That whole area was totally flattened during the Blitz when the SS Malakand blew up in Huskisson dock, so there is little to guess where the picture might actually be now other than by the remains of the track beds of the LNWR and L&Y.
Huskisson after the explosion....
So from looking at the old maps I think it is about
here