Willy creates an image of New England as near-heaven, full of many "fine and beautiful towns." But it not so much New England's aesthetics that make Willy long to return. It is the hope that the boys will see him in a new light, a light of success.
Willy's desire to go back is because of the "fine people" who live there. The "fine" are the rich whom Willy thinks have achieved the American Dream.
But for Willy, even better than rubbing elbows with rich people is being accepted in their social circles. "I'm important,boys," Willy seems to be telling Biff and Happy. "Value me. Watch me move among powerful men so that you can respect me and love me." Willy is so sure of acceptance, not only of him, but anyone would whom Willy might care to introduce them to. "My friends are their friends" he seems to be saying.
Here is that excerpt:
Willy: You and Hap and I, and I'll show you all the towns. America is full of beautiful towns and fine understanding people. And they know me up and down in New England. The finest people. And when I bring you fellas up, there'll be open sesame for all of us, cause one thing boys: I have friends. I can park my car in any street in New England and ten cops protect it like it's their own.