Put them into service.
They are probably the old returnable bottles, which are great for homebrewers.
Thicker, heavier glass, they were made to be reused-washed and refilled many times, plus the cases are heavier/sturdier. I have 5 or 6 cases.
Occasionally when capping, I'll break a neck off of a non-returnable bottle. This has not happened with the older bottles.
-Those that know don’t close the door on those that don’t know (The Gourds, "Education Song")...
-The brewer's yeast ferments, and forgives, all that you did...(The Gourds, "Right in the Head")...