Clifton Pottery Celadon Green Crystal Patina Vase (?)

Very pretty green pottery vase that I found at an estate sale of an art dealer who appeared to have had a particular interest in the Chicago Artist, Edna Wolff Maschgan. Anyway, in addition to the many paintings by Ms. Maschgan, there were numerous other interesting items including this vase. It is a beautiful green with slight blues falling down from the top into a sparkly green bottom. This is a very interesting glaze of which I know nothing. I'm hoping it is not a Crate and Barrell item. I really don't think it is.

It is marked on the bottom with writing, including a "'90" which I am presuming is a date - 1890? 1990?. Anyway, there are other numbers, a "991" or a "166" imprinted on the top and a "186?" on the bottom. I can't make out the signature - "Lofton?" I don't think that is what it says.

Update: Perhaps this is a Clifton Pottery (New Jersey) vase? Some of their similar glazes have been described as "Celadon Green Crystal Patina." Plus, the mark on the bottom looks similar to a Clifton Pottery mark.

Can you help me? Thanks!!