[Kevan]

The one I used is MasterFoil Plus non conductive adhesive LINK. 6mm seems to be obsolete but they still do 5.5mm which is pretty close.

You might like to try this eBay seller. LINK I haven't used this for a full track but have used it to repair a couple of breaks with excellent results. It has genuinely conductive adhesive and is cheaper with free postage.

I was asked to source copper tape so thanks for the links 

1/4" (1.25mil / 0.032mm thick) Venture tape -> https://www.creativeglassshop.co.uk/copp...-inch.html
7/32" (1.25mil / 0.032mm thick) Venture tape -> https://www.creativeglassshop.co.uk/copp...-inch.html

...but that link of yours looks good, 7/32" Crea Copper tape at 0.06mm thick (2.36mil) -> https://www.creativeglassshop.co.uk/copp...-inch.html