The Sagem can be used as a loopthrough,
the
Sky box cannot, and
I would not recommend the 5 way SCART lead at all.
So
RF lead
Aerial ->
Sky box - > Sagem - > TV
Use the secondary RF output from the
Sky box to power the VCR.
Then
SCARTS
VCR output - > Samsung input 2 -> JVC EXT 2
Sky TV output - > Sagem VCR input/TV output - > JVC EXT 1
Your TV should be able to loop the two SCARTs together should you need to record anything from the
Sky or Sagem boxes using the on screen settings, but you may have to experiment with switching EXT 1 and 2 round.