By no means take this as gospel as Peter says, Orrefors marks are very complicated.
Edward Hald' pieces from that era were often marked Hald, H, or Hd. I have never seen HF as a combination before. The date is sometimes shown, but with Hald, orrefors and the decorator's signature.
I'm by no means an expert on Hald, but I haven't seen this format of signature before, and it doesn't to me look typical of his work either.