Looking for goblin archeologist in Permafrost

[BornInOz]

I've been camped in Permafrost where the goblin archeologist supposedly spawns (421, 190 per the wiki entry). Per the wiki, he's a 20% spawn probability and I've been through at least 9 spawn cycles and he hasn't shown up yet. Since the spawn timer in permafrost is over 20 minutes, it's getting to be quite a grind. Am I just on a bad luck streak here or are there any known bugs with this spawn?

In case anyone is wondering, I was hoping to snag a dented brass mask as one of his drops, but at this point I'm looking at alternatives.

Thanks!