Cobalt blue large glass pitcher w/ applied handle - looking for maker

This piece was in a box lot I picked up at the auction a couple of weeks ago. I think it is hand blown with a polished pontil. The handle is applied & has an unusual (at least to me) button like mark at the bottom of the handle. It is 8 5/8" to the side edge.


Anyone like to take a guess at the maker?

Thanks for any & all advice or opinions!!!
Peggy

 

the button is a handlers mark. these are used by basket handlers. each has their own personal tool aka mark. looks recont to me.

 

Thanks George!!

I hoped maybe someone would recognize it & possibly know the maker. I bought the box lot for other things that will more than double my investment so this was just going to be gravy.