JR,
Is the Month also listed on the pink slip? As if it is September or later, it should be a '66 Model. I'll check on the numbers in my book when I get a chance to try to decipher it for you. It should also tell us the year of it.
The Model identification should be the first 2 Letters in your VIN. I believe you have an HM. If the Empty Weight of your truck is 8,200 and the GVW is 19,500, that means you can legally carry 11,300 lbs.
We have a couple of small Big Truck junk yards around here, but I don't remember any early model Hoods there like you have. As you may have already realized, it was not the best design and somewhere around '68 they changed to an improved type of Latch very much like the ones in the picture above.
My best suggestion is to start a new post here on Big Bolts asking for Big Truck junkyards anywhere around the country. You also want to consider changing your Hoods to the newer style, if you can't find the old style type parts you need.
You could also possibly convert your Hoods to the new style Latches with a little creative body work.
Bill