A ceiling Rose is such a neat thing - spaces for all the wires.
It's not surprising that you can't fit all the various wires into the terminal holes in your new light fitting - you will probably need some form of terminal box/strip well insulated and tucked up out of the way with a short run of cable from this to the new light...
In a ceiling Rose there are usually just two black wires joined together - Neutral in and Neutral out to the next rose - but you have three... It may be that the extra black wire is a neutral return from some other remote lamp but this is just a guess - it may be neutral to another ceiling rose.
In a ceiling rose there are usually three red wires joined together - Live in - Live Out and Live to the switch.
It's reasonable to assume that the red-sleeved black wire is switched live.
This leaves just one red unaccounted for - it may be that this is a switched live feed to another lamp and if this is so it will need to be joined to the Red-sleeved Black Switched-Live for the "other" lamp to work.
My answer here is just guesswork and conjecture based solely on the information provided - your safety should be your highest priority so take care...
Good luck...
Peccavi
December 2009
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