The Regensburg factory was only in business for 16 years, these were the owners.
BORHO, ZINKL AND CO. 1874-1875
ZINKL, THENN AND CO. 1875-1877
FRITZ THENN CO. 1877-1886
This large stein has no markings at all, but if you search for Fritz Thenn on line you can find John McGregor's Regensburg site. This one is listed as 1L #154. I tried to decipher the saying around the center piece with the1675 on it, but struck out. It might be part German and part Latin. It's about 8-1/4" to the top of the lid and almost 10" to the top of the thumb lift.
Borho, Zinkl, Thenn
|21.1 cm (appx. 8.2 inches.)
We see another item in our database with the same mold number and the same producer: