Collector Locations

Is there a resource that provides the location of Collectors around Ascalon?

In particular, I'm trying to find the location of a collector that collects singed gargoyle heads. I found him/her once, and she had a nice war hammer (+25 v Charr) for 3 singed gargoyle heads. I now have the gargoyle heads, but for the life of me can't find the collector again!

Any help appreciated,

Petrov.

The signed gargoyle head collector is in the camp right outside Ascalon with the Ambassador and the Elementalist.

EDIT: Oh, and I believe you need 4 heads instead of the usual 3.

I was wondering if anyone had problems with the enchanted lodestone collector outside the sanitarium. I had 23 yesterday when I first found her and she acted like I had none.