I'd say that beyond the fact that it has four engines and a nose it looks nothing like the X-Wing. Totally different silhouette, totally different aesthetic character.
Actually, if memory serves I think modern US fighter jets were the main source of inspiration. The mandate IIRC was to make a new, more formidable variant of the starfury capable of operating in an atmosphere. So the addition of aerofoils and a fuselage with a second seat are all logical modifications given the "real world" limitations put on Earth designs.
I always felt that the original model of Starfury, the MK-4, tends to resemble the gunstars from "The Last Starfighter" more than anything else.