Adam, left, and Jeremiah Babcock talk about the removal of the component pieces of the 18th-century barn they are disassembling. WILLIAMSTOWN, Mass. For David Babcock, deconstruction and reconstruction are two sides of the same coin and a part of who he is. Babcock is in Williamstown this month removing a 19th-century barn from a property on Green River Road (Route 43). In the not-too-distant future, he will be back in town putting the same barn back together on the property of the Williamstown Historical Museum. My father, he was farming back in the 50s, Babock said this week. He needed a barn, and my grandfather was a carpenter in Williamstown. . It was his grandfather who raised him, and he asked my great-grandfather if he could build a farm. And he said, There s an old barn up on the family property in Berlin, N.Y. We could go up there and take that down and bring it here to Hancock. My father was, I think, in his early 20s at the time, and he