This is a CD 156.1 Patent Other base embossed PAT SEP 13 1881. I bought it on eBay from a non collector a year and a half ago. It was actually listed as a Boston Bottle Works piece so I don't know how everyone missed it. It was dirty and soot covered. What looked like a nasty skirt bruise ended up being some pretty great looking phlegm in the skirt - a pleasant surprise.