If you choose to accomplish repairs on your own Polini 911 GP 3 then it is usually a good plan to have access to a Workshop Manual for a reference in case that you need to know the way to strip off a certain component including Dashboard and install it again effectively.
Polini 911 GP 3 Workshop Manuals can provide identifiable diagnostic guidelines for the car therefore if something is not working it can help you identify what the situation is and tips to make it better. You will be able to assess if this can be achieved yourself or that the job is simply too big you can book your 911 GP 3 in to a trusted car garage.
Polini 911 GP 3 manual