Good questions. Believe it or not, the bottom reads, or should read, PU 2944.66 P = Sven Palmqvist, U = handmade glass and 2944 is the Orrefors production number, which runs sequentially for all designers. The production number is assigned at the time the piece is designed and stays the same throughout the period in which the piece is is made. At first, I read the writing as O = Orrefors N= Nils Landberg, but a check of the production catalogue showed it to be a Palmqvist piece.
I'm not sure what the "66" signifies here.
Hope this helps.