Heads of Hancock

When going to/from upstate I normally stop in Hancock, southeast of Binghamton on Rt. 17, for a snack break. On this trip I learned that the bakery/restaurant I sometimes eat at had gone out of business. However, these mysterious busts are still in the windows of the Two Rivers Trading Co. across the street. They look like plaster casts of real heads. Many are wearing respirators. Why are they there? Who made them? What do they mean?