I am using the scart lead at the moment, but having no luck.
However, your idea of using a co-axial cable between the VCR & STB is something I should have thought of.

Trouble is I'm 82 now and climbing about on my knees changing my specs to read the inputs and outputs is not a barrel of laughs (accept for by standers)
I will have a go at your suggestion tomorrow. Thanks Rob.
Ron.