The paragraph does seem very convoluted to me but I'll try my best to help. I assume the first sentence is saying Larborough is a place defined by, or at least seen for bicycles, small arms, tin-tacks and "Cowan's Cranberry Sauce" which could be a famous or well-know sauce? "A million souls living cheek by jowl in dirty red brick" I think refers to a substantial number of people all living very close together in perhaps dirty red brick houses? "Atavistic" describes going back to something more primitive/ancient and grass and earth I believe refers to simple nature without evidence of civilisation (man-made structures like houses). The last sentence possibly is stating that Milford is either completely civilised or primitive/natural, not both. "A race that demanded with their grass and earth both views and tea-houses" refers to people who want both? I hope my explanation was at least a little helpful!