I was thinking of just adding shot and some kind of plug to keep shot from falling out?
Not a good idea. Without knowing what powder and how much is in each case, you are asking for trouble.
A. Those appear to be standard Remington - Peters 38 spl cases, that's good.
B. It would appear that someone put a drop of wax into each case to seal it, that you will have to check out for yourself.
c. They do have a roll crimp on each case, not sure why, unless it is to insure that the wax will not fowl the forcing cone on the revolver.
I would guess that someone made up a batch of practice ammo for indoor target practice in their basement with enough wax to mark the target and just enough powder to push the wax (or plug) out the barrel.
Can you use them as is, that is a BIG, NO, unless used for the purpose they were made for.
There will not be enough powder in them to push anything other than what is there now. They will stick bullets in the barrel (squib) and tear up your gun. And shot will not work much better than hitting the floor right in front of the barrel.
These are all guess and without taking one apart there is no way to tell what you should do. Me, I would take them all apart and use the case and primer to do my own loads.
Get them to an experienced reloader to find out what the story is with them.
Good luck and stay safe.
Jim