These flights are not operated by Pan Am. The website may lead you to believe that, but they are actually operated by Boston-Maine Airways. BMA is the non-union equivalent of Pan Am with lower paid, lower quality pilots and staff that often have checkered pasts and are willing to take jobs with marginal airlines like BMA.
Pan Am recently announced it would shut down its operation effective October 31 (to eliminate the unions and transfer all its flying and operations to non-union BMA). An injunction was ordered by the court to stop the shutdown and obvious violation of the Railway Act. Search Google news under Pan American Airways Corp for details.