Rule no.1 - always note the connections before you remove the old
rose!

:-)

From what you have said, I would deduce the following:

The black wire wound round the dark grey wire is neutral.

The 2 red wires wound together are live.

The black wire on its own is switched live.

Use a test screwdriver/ multimeter to deduce which wire is going to
your wall switch and open the switch as well to see what type/colour
of flex is present there.