Just to throw this out there, I've found a few things with the Lenox 100:
Firstly, print on the rougher side, not the smooth side. The smooth side gives blotchy and un-repeatable results, with less density. Second, it likes a brush coating so you can work the solution into the texture.
If all else fails, try adding a little bit of oxalic acid to your ferric oxalate, or call me and I'll send you a free replacement with the oxalic acid already added. The Lenox paper is just on the border of needing a acidifying stage, so I find myself adding about 2g of oxalic acid to every 100ml of ferric oxalate, just to make sure the pH stays low.
I'm looking at adding a couple more papers to our catalog, but they are all in the price range with the Fabriano and Platine. I'm still searching for the holy grail, a cheap paper that holds up to the processing while providing a good image without any pre-soaking or jumping through hoops. A $500 B&S gift certificate to anyone who can steer me to a paper that fits my criteria!