Nice unsigned PY weight.
It is a design that I have called "Horizontal Twists
" rather than just "Concentric". Most of these have fairly "chunky" white or yellow twists but in some the twist canes are finely made. Also, examples with two rows of horizontal twists are less common than those with the twists only in the outer row. Butterfly canes in the outer row make it a bit more special.
As Roger says, care is needed, as with many of the unsigned Ysart and similar items. A similar design was also used at Ysart Brothers (Vasart) [or earlier] probably made by Salvador Ysart. I have an example shown in my web pages
, but when compared to a PY version the differences start to be seen and cane matching helps to confirm things.
On the point of cane matches, people have claimed that the butterfly cane was made by Paul Ysart. But there are (at least) three types of butterfly cane known and the one in Roy's weight is an example that can also be found in Ysart Brothers / Vasart / Salvador / later Vasart (and other?) work!
However, so far I have not seen any butterfly cane used as a part of a concentric row in other than Paul's weights. So that alone is a fair clue to the maker of the weight ... until we find otherwise, of course.