It's a very nice piece....but will wait for clearer pictures before I give an opinion.
Could that mark be the mark of Colonial Williamsburg Reproductions?
Linda C

I'm wondering if this piece is by the same potter?

Here is a link that might be useful: EBay Link to MPM Pottery Piece

justlinda - thanks, googling it I was coming up with Miessen and I know that's not right. That candelholder even has the same fluted lip.

Sorry, that should have been Meissen. But thanks for sending me to eBay, I found more incl this one. My vase is 8.75" high, the mark I couldn't figure out I think is "slb". This one is from the same maker, obviously a big difference b/t number 21 and number 612, but look at the price! A couple of smaller ones listed too, but I'm not sure sellers know what they have. I emailed all of them, will let you know what responses I get (if any). Last time I emailed ebay sellers looking for info on my great-great-grandpa's Victrola, eBay told me someone was using my email to spam people.

Here is a link that might be useful: mPm pottery vase

I have that same vase, or at least one with identical markings and design. My husband brought it back from a business trip to Salt Lake City. Mine has an additional mark on the bottom with the date "May 8, 1990." I know they also made lamps with the same base. I never considered the vase particularly valuable or, to be honest, beautiful (I never liked the blue on it), and I think it was fairly common. It does make a nice heavy vase for summer flowers, though.

I have nearly the same vase that i just found at a thrift store. This is what mine looks like.