My apologies. I think I paid too much attention to the fact that just the company name was on the bottom. I didn't think it through and ask the chances of this happening to an engraved piece. Not likely. Looking at the piece again, the style is very much pre WWII Orrefors, and the design is close in style and content to some of the pieces that both Gates and Hald did. However, in a quick scan I wasn't able to find a match for the design in "Swedish Glass Factories," which includes catalogues from before WWII. Also, in the 30's and 40's Orrefors glass had a wealth of information on the bottom.
I'll suggest two possibilities: First, this is an anomaly as no production number, designer or engraver's code is on the base, but it is genuine quite early Orrefors. Second, this is a copy of Orrefors style on which someone has written "Orrefors." The second option isn't totally outlandish, as recently we had what appeared to be an unsigned Orrefors Javanese dancer vase which matched exactly a model in the Orrefors catalogue. I was convinced that the piece was an Orrefors anomaly until I found an ad in a post WWII Czech Glass Review showing the exact same design made at the Lobmeyr works, unsigned.
It would be great if one of the real Orrefors experts, Bill G and Dan S, could comment on this. Very interesting piece.