OK pulled one wheel off and found this.
Pictures at link below
https://1964chevyp10.blogspot.com

I was able to shine a light into the small hole in the front of drum and rotate the drum to where I did see an adjuster at about 6 oclock.
Also saw what looks like a brake hold down spring just floating around loose inside the bottom of the drum.
Looked at the backing plate and the pin that holds the spring holder piece is gone so 1 of the shoe holders is obviously not on.
Started wacking the drum with a rubber mallet and I guess its rusted to the hub. Don't see any space at all between the axle part (end flange piece) and the hole in the center of the drum? Not even a little crack?
Going to soak it with WD 40 on the lugs and the pre-drilled out holes of the face of the drum/hub intersection.
Don't have a drum puller so going to soak and the wack it with a rubber mallet and see if that works.
If not I guess I'll have to buy a puller.
I'm a little concerned that the axle end flange is holding the drum on.
Am I correct to assume that the axle flange is not over the drum but just very tight to the inner circle of the drum itself?