Excellent question Dana. My speculation is that the Bridgton handcars were purchased by rail enthusiasts prior to the railroads abandonment.
Although Ellis D. Atwood purchased much of the former Bridgton equipment, it was said that the scrapper cut up some of what Mr. Atwood had planned to take with him to South Carver, MA.
I understand that a watchman was hired to keep an eye on the equipment until the loading and trucking could be completed.
It has always struck me odd that the body of Bridgton railcar no. 2 was left all these years to rot at the Junction. Supposedly the car was tipped over and the frame and running gear removed for scrap or other salvage.
Perhaps a handcar or two met similar fate, being plundered for the iron.
I'd be willing to bet that within old correspondence between such fans as Linwood Moody, Edgar Mead, Eric Sexton and others of the period who closely followed such things, is mention of those handcars, etc.