Avira, nice town. Might be your great-grandparents were in wood business, sending it by the river.
This is close to an area where some of the Vilno Rabonim, like R Grozdinski will go for the summer, so they might have stopped by them.
Wiki and others list 3 shuls, schools of multiple derachim, including Zionist, all for 2000 Yidden. So, it was indeed a heterogeneous community. several photos shows one picture of girls in berets, the rest look like not-so-observant