Hello I've been trying to do some research myself.
There was an Ullersdorf in Bohemia, close to the German city of Zittau, it was probably closer to Hradek nad Nisou in the czech republic.
I know that the Zimmermann and Tschiedel names are/where quite common around that area until the end of WWII.
My Grandfather's sister (Motz) married a Emil Tschiedel and they had a son. All three were killed/died during WWII.firstname.lastname@example.org