I am 39- one of three brothers (all still in the area).My Father is still alive. He is 66.I imagine my father would be your 3rd cousin and I'm your 4th- though I am not sure how that works.Your father, Bob, was my grandfather's cousin.So would that make Bob my father's second cousin and thus you his third cousin and me your 4th?I am no expert on this.
I remember the HJ Dowd Paper Company from my childhood as the trucks were quite common around the Boston area with a distinctive yellow logo.I believe the company was sold to International Paper in the early 80's.
Again, my father worked briefly for the family business before going to work for John Hancock Insurance where he eventually became the president of the real estate investment division and retired in 2000.He also lives here in Boston on the waterfront.
I believe my mother crossed paths with your mother as a real estate agent in the Weston/Wellesley area.My mother was Mary Ann Dowd.She passed 5 years ago.I believe my father attended Bob's funeral.
I notified my father of this post and he could give you much more information than I can and he would love to hear from you.
His email is firstname.lastname@example.org
He has pictures and films with your grandfather and possibly your father in them.