For search ref.: A.K.A. Derpt, Tartu, etc.
Please leave photos and let us know what you found including sources. While there were Baltic Germans in Dorpat, it was largely shuffled between Sweden & Russia as far as official political control. Prussia is, of course, before a unified German State...but it does not extend that far east (officially, that is). Anything you have found would be of great interest as this region needs extensive documentation (see member Zolotnik's previous mention of trying to collect information lists on makers for this area).