I posted this picture on one of the doll boards and the consensus of opinion was that it was from a hair net. I wondered how could this be? I got her several years ago and her hair hasn't been netted for a long time.
Here is an interesting explanation:
do repair and restoration of dolls and have seen this before. the rubber in the hairnet edge will deteriorate and before it even does it can make a mark, sometimes not showing up for a while even years. It all depends on the hairnet, and the rubber used, mostly now they wrap the rubber in white poly thread but if the rubber is strongly "unstable" or badly produced (just like the plastic parts of a doll oxidize) it can react and start to seep into the vinyl and may not change color until later, we must remember that plastic,vinyl and rubber are all rather "fluid " materials atomically, and their structure is constantly moving. so what shows up on a surface now may disappear or move inward to the interior or outward to the surface. the color of the mark has distinct properties, green being a color that appears with a stronger copper content, and the rubber used could have been exposed to copper somehow (or brass etc) therefore making the greenish mark. An example of rubber affecting plastic is evident in many dolls like Dawn, that have rubber vinyl legs and plastic hips - they melt into each other sometimes and it really depends on the way the rubber and plastic is batched before being used in a mold part.
This is an Integrity Toys manufactured Gene Marshall.
When does one just give up? I have no more replacement Gene bodies. I've used up all of them replacing deteriorating IT bodies and replacing a few non-articulated bodies on Ashton-Drake Genes.