So, this place is currently located in the city of Tallinn, in the Põhjala Factory, nestled in the protective backyard of the Improv Theater Impeerium (Empire). A Google search for Põhjala sepp should take you right to the spot.
The address is Ankru 10, and you can reach us by phone at +372 503 8593 or via email at rain@hephaistoslab.eu.