I'm really curious about these. Particularly those that are a bit more ornate such as yours and the one sold by Fieldings. They remind me of Loetz Octopus vases - I've always thought the Octopus vases were some form of airtrap but never having owned one I've not really looked into that observation. However, your vase immediately brought to mind my Octopus vases interest. I've just had a quick google and found a fascinating article by Galle all about the Loetz Octopus vases and their patented method of making here:
https://www.loetz.com/featured-articles/loetz-octopus-victoria-and-the-english-connectionSo, the information in Galle's article is extremely interesting. I'm very curious to know whether your vase and the Fieldings one are English? or maybe they aren't? Could they be Bohemian maybe?
What I like about them is that they are very 'freeform' design of airtrap as opposed to, say, the airtrap criss cross, lined and dot vases , which seem to me to be uniformly patterned across the body of the vase.
I'm just idly wondering about Harrach if I'm honest.