Whichever way you go you'll need to drill out the flash holes as much as you can and still leave enough shelf for the primer to seat on. I think 1/8" would work with LP primers.
Otherwise, the primer will back out and tie up the revolver every time he pulls the trigger.
Don't use these cases for anything else.
I'll be reloading them for my dad. He just wants a cheap way to practice drawing and firing his revolvers with some recoil if possible.
You won't get any noticible recoil with anything mentioned here. If he goes the primed brass route, caution him to only do this outside as pimer smoke is not healthy.