You've gotten the advice you need on wiring. I just want to add something on painting needles. It can be done but it's a difficult job IMO. Any misstep and you're in trouble, and I don't think they ever look right. You can find NOS ones still for around $50, except the speedometers which run quite a bit more. Occasionally see a KPH one on ebay for $95 if you don't mind that. It's for a later truck going 140 kph/85 mph.
