I have a UK '95 Audi A4 1.8 20V and the other day my instrument cluster packed up.

It is displaying “Def” where the mileage supposed to be? Has anyone got any ideas on this? Is it something I can fix with a VAG COM tool? Or is it a replacement job?
If it is a replacement job then could i fit a cluster with a trip computer on it? BTW for reference my instrument cluster is the one with red dials and no middle LED screen.
Answers would be greatly appreciated and I know a lot of the you lot on this forum is greatly experienced Audi techs. Plus the Speedo and rev counter go up excessively high when revving or driving the car.
E.G. when driving at 40 mph the Speedo reads at over 80 mph.
any thoughts? Would a VAG COM be able to sort this out? Please bring back some ideas, as I haven't got much time left until a vehicle inspection.

Hope to get a response soon!