B-body inner fender - what's this hole for?

I'm just using this photo for reference BUT my '69 Plymouth inner fender (NOS) has this hole - what's it for? Its threaded.

the short "J" bolt for the battery hold down

Threaded?

Shouldnt be threaded.

But like mentioned.
Inner battery hold down J bolt

J-bolt ... that makes sense. Pretty sure its threaded - which is part of the reason I was baffled.

*Should* be just an unthreaded hole. If they were supposed to be threaded for a bolt, they would have a nut plate like the battery try mounting holes a little further down.

Yup, took a closer look and its not threaded. But its "punched" in instead of a clean stamping - jagged rough edges on the wheel side.