Hi David,
Like most glass the labels disappear eventually.
I am trying to clarify whether individual production units did use labels, at any time, before and after 1958 when most units were incorporated into VHJ Obal, then Sklo Union. Clearly Rudolfova Hut' did so until 1958. These are seen fairly often, alongside the Glassexport Bohemia Glass label.
At the moment I have not found any evidence that other units did.
I am also interested in seeing whether any pressed glass items made in the Slovak factories appeared with Bohemia labels, before (but not after) 1965.
Thanks again,
regards,
Marcus