This 1941 Ford delivery van is an interesting piece of our nation's courier service history. The seller notes it belonged to the Railway Express Agency, which has a fascinating history as a government monopoly created in response to WWII.
You can still find scale models for Railway Express Agency vehicles, which gives you some sense of the organization's significance when it existed. It relied extensively on rail transport, which leads me to believe this Ford was used for transporting packages to and from the railyard. It's not surprising to see it in Western Mass., either, as transport routes between Boston and New York were heavily traveled.
It's near impossible to tell just how rusty this Ford is, but take a look at how much the fender has been pushed back by the tree - think about how much time had to have passed in order for the tree to grow to the point that started pushing the truck out of its way! It's difficult to assess the potential here, but the low asking price may make it worth taking a trip out to Western Mass.
The truck is now free from the tree!