Just about to order the paint for my '79 Series 3 safari backed landy and the paint colour I had been expecting does not seem to be the correct one.

I had assumed that Marine Blue was the correct colour but now having looked at the colour car from Tekaloid it seems that this is far from the right blue, having looked around I see that Tuscan Blue was available in '79 so wonder if that is in fact the right colour: an image to see what people think might be the right shade:

take into account paint fades over the years, try t cutting a small patch on your landy and then match against your new colour,

Looks like the Marine Blue that I bought from Paddocks

Paint shades vary from diffo manufacts, and as stated that blue will have faded.
Bit late now, but auto body places will mix you up a colour to match owt you want.