Emulsion update ...
My test sample treated with sulfuric acid is showing no signs of yielding any biodiesel, unless biodiesel is a deep sort of midnight black. Under that is something that's a lighter colour, but I don't hold out much hope for that being bio.
On the up side there's about an inch and a half of what looks like it might be bio at the top of the sight tube. I recon that probably equates to a yield of around, ooooo, 6, may be 7 litres from an 80 litre batch.