a couple of questions

[john12glen]

  I see from the NGJ that Dapol have some new junction and bracket signals, but are not on their website, any ideas?
I did look, honest, but can't find the definitive glue to fasten Plasikard to mounting card.  TIA John

[ntpntpntp]

Can't help you regarding the Dapol signals.

For gluing plastic to card I'd suggest something like UHU general purpose adhesive.   Not superglue.
Actually I'd probably try PVA first as that's my go-to glue for most general scenery work on the layout   but if you want a better bond I'd think you need something which does chemically react a bit with the plasticard not just sit on the surface.