I also believe, as does M, that this is Harrach production. Although there is some of this production attributed to Kralik, I believe it is actually some confusion due to a Wilhelm Kralik working as the Administrator at Harrach at the time the glass was developed. A British patent was issued in 1880 to a Wihelm Kralik. The patent was issued on behalf of C.N. Blumberg, who was apparently a major importer of Harrach production to the UK at the time.
This is not the same Wilhelm Kralik who was the owner of Myer's Neffe, as the time frames are not correct. Wilhelm Kralik of the Myer's Neffe connection died in 1877.
Craig