Tis done!
Thank you again to everybody for both the practical and moral support :-)
I went for a 20 AMP choc-box as I had 3 wires on the ring to contend with. Used one side for the lighting ring leaving the other for the flex from the chandelier. Cut a big enough hole in the ceiling to push it in (wore my mask with 2 x side filters as it is Artex in a 1983 house). Then drilled the 5" wooden pattress so I picked up the joint with both screws and screwed it up as a test so I knew it all fitted.
Then fitted the chandelier to the pattress, balanced it a bit on the up-lighter, made the connections and screwed the pattress up. All the affected lights are working - although at some stage I'll have to decide whether or not I want a new outside light, 60 watts seems a bit pointless outside.
On the kitchen light front I went for a 5' tube at 5,400 Lumens and in my
15' x 10' kitchen it shines into every corner, so much so I'll have to clean the air fryer! The clips and cable fought each other when fitting it but they all seem to use the same method. If anybody is interested: