I have four of these stems.  They are amongst my oldest purchases.  I don’t think I’ve ever used them.  Too small – sherberts.  The birds fascinate me, as does the name.  They were produced by the Fostoria Glass Company of Moundsville, West Virginia, between 1918-1928.  I think I bought these stems online, but can’t recall.  I’m always surprised, given their age, that these glasses aren’t hugely expensive.  I’ve never seen them in a shop ‘live’ but watch them online.  There are a number of etches with birds, from different companies.  I don’t own any others, but….maybe some day!