Hello Delia,
I was none too pleased with that image myself. Let me make another attempt within the next 24 hours.
Regards,
Adam

Thanks.
Glass is very difficult to photograph - there's no hurry on my end.

Good morning Delia,
As requested,I added two more images of the signature which appear to show more detail. Hopefully you are able to access them on your end. Please inform me if you are unable to view them.
Plus,it appears I made garden variety error in my description. Art Noveau,not Deco. I should have caught this.
Many thanks,
Adam

The photos are fine, Adam, thank you.
This is an interesting vase in that it seems to combine the restrained symmetry of Art Deco with the flair of Art Nouveau. I've also played around a bit with different spellings of Lonsdale (Tonsdale, Lonesdale etc) and am coming up dry for a confident attribution.
I'd be happy to run a photo of the signature and vase by an expert in early 20th Century glass for their opinion if you like? there won't be an additional charge...but it may take a little longer than the 48 hours we complete appraisal in.
Let me know if that's OK?

Delia,that would be wonderful. I am not particularly constrained by time.
Adam

Adam,
I must apologize PROFUSELY for my inexcusable delay in finishing this appraisal; the colleague I reached out to overlooked my email and this got buried in my inbox and didn't resurface until we did an audit. However, I'm happy to say that I've been able to determine that the maker was Honesdale; several similar vases have sold for between $300-600. I'm not quite sure why they're all called Dorflinger (possibly the designer but an extensive online search as not unearthed that). Regardless, I'm pleased I could find this and am so sorry that it took so long to do so.
Best,
Delia

Delia,
No apologies necessary,I assure you. It was a pleasant surprise to see a response to my long forgotten query. The actual owner of the vase will no doubt be delighted by the information that was gleaned by your research.
Another inquiry,if you please. Could you put me in contact with an individual or establishment willing to purchase this article? Or would my best option be to contact a reputable auction house(ie,Heritage)?
Thank you for your efforts. Certainly better late than never,hey!
Regards,
Adam

Thank you!
If this item has a status "for sale" and is "public," then it is probably already on our marketplace and people can see it and make direct offers to you (you are not obligated to accept any of them).
If you wish to sell this at auction, you might reach out to Andrew Jones Auctions, or Bonhams...both are in Los Angeles, which may be the most convenient for you. Heritage is also certainly a good choice, too; they don't have a decorative arts specialist in Los Angeles but Nick Dawes, who heads their glass and ceramics department, will be able to look at photos and let you know if this would be appropriate for one of his upcoming auctions in Dallas.
Good luck and do let me know if you need additional references, etc.

Delia,
Thank you so much for the information which I requested. You have been a wonderful resource and your attention has been greatly appreciated. Should I need further information I will be sure to contact you.
Regards,
Adam

Many thanks, Adam, and best of luck to you!