Glashütte Holsthum was set up in 1769 by a Dominik Laeis active until 1811/12 and again 1843 to 1850/51. Buildings largely modernised but including cone roof still exist. At the time the area was under Austrian control. A book was published by a descendant Ernest Dominik Laeis in 1831 and mentions the Glass works. https://books.google.co.uk/books?id=TRNAAAAAcAAJ&dq=laeis+Glash%C3%BCtte&source=gbs_navlinks_s
and more recently Josef Dreesen: Die Glashütte in Holsthum bei Bitburg. Neuss 1990. Which can be found cheaply on Abebooks, if your Joseph Greiner was an important part of the business he is likely to be mentioned in that book
Only other glassworks that I find was a bottleworks set-up in 1868 not far from Holsthum in Minden.and various name changes to 20th century. Meyer & Söhne in Porta-Westfalica. Also (or probably same) Glasfabrik Wittekind -. Part of Gerresheimer company in 20th C making carboys. These might point to earlier glassworks there.