Geocaching is a worldwide scavenger hunt that uses a GPS or phone app with GPS. There are over 3 million active caches around the world. Some are as small as a dime, others are big enough to walk into, all of them provide a unique adventure. We invite you to share your stories, photos, and experiences!
If I happen to have a spare container with me, usually I'll replace a damaged one. IMO if you found the original and know where it was, that's not the same as putting out a random throwdown for a missing cache.
If it's a specially made container, I'd probably just log Needs Maintenance, but if you're just replacing a pill bottle with something similar I would think it's fair game. In any case definitely mention it in your log
I wouldn't do any maintenance, it's up to the CO to care for the cache. And throwdowns are generally frowned upon. But do log a Need Maintenance log so the CO gets informed that there may be an issue with it. As a CO myself this is what I prefer.
The CO may be inactive and the cache is abandoned, but then the spot will open up again and someone can place a new happy cache in it's place.