Here's the finished article, and guess what...no glue!
I cut some scrap paper to the right high to match the container and wrapped it round.
I used some washi tape to seal the join and then, as it didn't quite reach the top and bottom or maybe my cutting wasn't quite straight. So I put a strip of washi around the top and bottom too.
Then I had to try and cut a slot in the top, which was not so successful.
It involved a wine bottle opener and some very bad attempts at cutting with scissors. It's a pretty shocking attempt, hence why there's no close up of the top! But it does the job even if you can only put in one coin at a time.
But now I can free up the mugs that were holding coins and put change straight in our holiday fund!