Altering the wiring of switch for the stairs / landing. Old colours.

[madmickshere]

Help needed please. I intend altering the wiring of the switch at the bottom of my stairs. As you can see on the two images I have added the wiring is in red, black and green/yellow. Looking at the back of the double switch, the one on the left side turns on and off the light at the top of the stairs (as does the switch on the landing). The one on the right turns on the downstairs light and an outside light at the same time. I would light to rearrange the wiring so the lefthand switch turns on and off both the down and upstairs lights (as I would like the upstairs switch to do also) and then I would like the the right switch just to turn on the outside light but for the life of me I can't get my head around this so any help or advice greatly appreciated. I have restored 3 houses and done lots of electrics on them but on this I'm having a mental blockage.

 

[EFLImpudence]

Not possible.

Obviously the right hand black wire goes to downstairs and outside lights so that would have to be separated wherever it is joined.

If you did that and ran another wire to the switch, you could have three switches.

 

[EFLImpudence]

It makes no difference, but you haven't drawn the diagram as the wires are.

 

[madmickshere]

How correct, as you say it doesn't make any difference