Old light switches wiring

[MalcolmS]

Hi All,
I have these old light switches.
I understand this yellow / blue is the old pre 1980 colour scheme.
Is it correct that:
1. YELLOW with a red sleeve is LIVE
2. BLUE with a red sleeve is NEUTRAL
?
Thanks

 

[MalcolmS]

I have put everything together as it was. The ones with black insulation tape are the ones that use to be live I labelled them days before the problem occurred.
I checked each wire individually and they are holding firm, not loose. The downstairs light works, the upstairs one does not.
With a torch I checked for any extra wires in the boxes and pull cord switch (a hole where the single 1.5mil wire comes out) but there isn't anything else.

 

[westward10]

Time to get an electrician.