Dan - I've exhausted my search resources for the defrost vent. You might want to give Tom Myers a call at (918) 542-3871 or Ken Neil @(918) 605-2248. They both have salvage parts for the old trucks.
But I tried, didn't I? ... At least I did that. RP McMurphy The past belongs to the future...but only the present can preserve it. Besides the noble art of getting things done, there is a nobler art of leaving things undone.