where can I get a custom dashboard for a 1975 dastun 620

Depends on what area you are in and how much you are willing to pay. My buddy has a plasma cutter/table and is very good at welding so he could potentially make you one if you gave him dimensions and such. I would look for a custom welding shop in your area and either take them the truck so they can weld it in place or give them dimensions and you could have them weld tabs on to meet up with the existing bolt holes.

I live in Rapid City SD and I think there is a place I can go thx for the advice and you gave me some ideas thx