How to reset focus, take off viewing lens, open back and tape paper with longs drawn on it to where the film sits. Shine diffused light through the paper. Set taking lens to where you think infinity is.
Take dslr with live view, set lens to infinity and look through the taking lens of lubitel. Adjust taking lens until the paper's grain can be visible, the peak sharpness. That is your infinity focus. Put on the viewing lens having it against it's infinity stop.
Congratulations, you've re focused a tlr alternatively send it to me and I'll use it like it should be used.