I've been looking myself. The newest knitty yarn roundtable reviews Eskimo by Garnstudio, which is 2.5 st/in, and if you use smaller-than-called-for needles, you might get the 3 sts/in gauge An Unoriginal Hat calls for, yes?
Can't hurt to try it. You only get 50m for 50g of Eskimo, and I don't know how much yardage (meterage?) the Blue Moon Fiber Arts "Leticia" had per skein (pattern calls for 1 skein.) Leticia does NOT seem to be listed on Yarndex...
Go for two, make sure you get the same dyelot if possible, and post your finished hat back here if it works?