1965 Dash - How should I clean/Restore

It's light rust under the paint, so sand it to bare metal, get as much rust off as you can then treat it with a paint-over-rust product. POR-15 is a well-known brand but Duplicolor makes a similar product that is sold at O's and A stores over the counter; a spray can will cost you about $8.

Color of the top coat is totally up to you. If it were up to me, I'd go with semigloss black.

The biggest part of the job is getting the dash out of the car.

I absolutely love POR-15, but don't use it on the dash; it's better for places that aren't seen, despite its smooth glossy coat. It does not stand up to UV light well, and paint does not stick to it.

I think that with the light rust you've got, I'd get some phosphoric acid, and clean it up with that, then wash it to make sure it's all gone. After that, sand it smooth, and then paint it with the color of your choice. You'll definitely want to remove all the body panels and dash parts that you don't want paint on.

Even the windshield will probably get misted with paint, so the more you can do to prevent overspray, the better.

I agree that it needs sanding down and repainting; white would be original except 'white' comes in a thousand shades. You can buy original color, interior spray paint which should be close since you will spray the entire dash. I agree that POR-15 is a bit extreme and likely won't look very good either. Its not like the dash gets splashed with mud and road salt.