unusual spatterware beer jar

I have recently adquired a ceramic beer jar that presents details that confuses me a little. I have been studying this jar and its design and the techniques are characteristic of the very well known term SPATTERWARE POTTERY. This jar can be American, English or just a copy. Moreover, the strange thing here is the rareness of this piece that at the bottom has a mark, while pieces of the same patterns did not have mark at all. I hope you could help me to know more about this unusual case and together find out what is the real thing in this and get to this jar=92s origin. I would really appreciate if you could give me any e-mail address where to send you photographs about this mark