Ivo mentionned a couple of months back that a cut rim is a trait of Bohemian / Czech manufacture altho I must question him more on this. (poor Ivo) I don't know if that apllies only or particularly unfinshied rims whiah was under discussion then. I also don't know if it applies only to a certain quality of item, cetain makers or certain periods of time.
Is the rim on this polished ?
One feature I do notice on Bohemian pieces of this kind and period is the rounded edge base. Often the bidy is pushed down so as to make a kind of hollow foot. Here the lower part is somewhat conical which I don't recall seeing before.
The applied tadpoles (for want of the proper term) I have seen on a number of bohemian pieces but this feature was also used by a number of English makers: Webb comes to mind and possibly also Powel era Whitefriars.
The fine internal vertical optic ribbing I have on a couple of pieces of my own, one of them a bulbvase. I don't know if it is a Bohemian trait or if it has any other significance for ID.
You seem to like pieces with a very subtle irridescence, as do I. The Bohemians did use irridescence quite a lot and the more subtle shades are quite beautiful IMHO.