Dash display gremlins

[Speed 3]

When I bought the Tuscan a year ago from a well known specialist it was displaying a fault code C. There is no actual fault with the level or the sensor. He told me that whilst I could send it away for refurb, there was a high risk (in his experience) of inducing other more permanent faults in clearing this one. It remains on to this day until cancelled with occasional code E's beating it on start up. Neither affect the running of the car and the report from the technician off its 12k service at 54k last week was that it was one of the strongest original engines and robust cars he'd seen.

Question is, should I attempt to have it rectified ? Its also just started to show some pixel graining on the clear areas (looks like dust in the LCD). Anyone had similar or have more expertise ?