Shouldn't be a problem, huskerguy. I've used Testors canned enamel primer underneath color coats without any adverse effects. Just let the primer cure good and hard before spraying the color over it.
My favorite primer for parts that have been puttied, filled, or formed from diverse materials is Krylon's big old can of sandable primer. It's cheap, fast, easy and, if applied carefully, gives good, uniform coverage. For small or intricate detail parts where you only want a base coat, I stick with an airbrushed acrylic primer.
Glenn