I did what I should have done in the first place - emailed Orrefors. They were very kind and immediately identified the piece. Ross, you were right about the number! I'm curious to learn when it was produced, and what the name of the series was (I asked, and I'll let you know what I hear).
Good lesson for a newbie - ask the company first! Thanks for your help, everyone, John
Your vase was in a catalog from 1972 and the designer was Sven Palmqvist. The article number is 4046 and it was eight different vases and bowls.
Your size have the article number 4046-121.
Lena and Kia"