OK, will create it as an issuer, but am trying to understand if the correct placement is Bohemia > Silesia > Guben, Town of … or Germany > German States > Guben, Town of.
From the description you posted, it sounds as if it was Bohemia > SIlesia at the time these were struck, but the Kunker listing clearly has it in Brandenburg (so, Germany > German States)
The mint is already in the database because coins for the Polish-Lithuanian commonwealth were struck there in the 1750s.