|Tip o' the hat to Marco Langbroek for passing along this image of the Campitello Quarry birch-tar hafting mastic adhering to a couple of what look like exhausted bifaces.|
The article in question is another one suggested by Marco Langbroek, Mazza et al.'s 2006 'A new Palaeolithic discovery: tar-hafted stone tools in a European Mid-Pleistocene bone-bearing bed,' Journal of Archaeological Science 33:1310-1318.
Stay tuned. And fear not. The Subversive Archaeologist is on the job! [I can't help feeling a little like Sherlock Holmes at times. You wish, Rob!]