Is “The richest man in Daming Prefecture” true?

In the novel, Lu Junyi is a wealthy merchant from Daming Prefecture in the North; there is no record of him in official history. Although his name appears in "The Great Song's Xuanhe Legacy," his identity as a wealthy merchant and the capture of Shi Wengong are fictional additions by the novel. The original text states: "北京城里是有个卢大员外，双名俊义，绰号‘玉麒麟’，是河北三绝" It also says: "他是北京大名府第一等长者" (from "Water Margin," Chapter 60)