Looking for these screw fasteners, or spec to hunt down. I think the (20 screw fasteners secure the window channel.
Okay Allen ; Try Evan or Joe (Mothertrucker) of this site, they'll have what you need on some old junk door . Your signature fails to mention your location and that hinders anyone near you from helping out . If Joe or Evan come up dry, try Chevs of the 40's in Washington State . Keep us posted .
O-Kay then, now we're making progress . It matters not if you're on the Colorado Plains or Mountain High, there should be some old farm / ranch trucks moldering within a few hours drive . The doors on the BIG trucks are the sane as on the pickups and if you find one that's bent or rusted out it should be dirt cheap . Keep us appraised of your search . I dislike Clutch Head screws intensely, of course my unrestrored '46 3100 and '49 3100 had them as manufactured, the guy I sold my '46 to was ecstatic . Back in the day NAPA stores had the best quality Clutch Head driver's, low quality ones tend to slip easily .
Why I mentioned the good clutch head screwdrivers I got at NAPA ~ back then I was making $100 / week so any new tools had to be really important and carefully budgeted . I guess when they were new in the 1940's they weren't rusty or filled with too many resprays........