I would also suggest the Tavern Puzzle's Captive Heart and Tridiculous along with Iron Heart. The heart shaped ring piece in the puzzles allow theming around Valentines Day or special memories for couples. I also used Self Restraint. If you can find the jumbo size (large spike type nails with rounded points} of Twisted Nails, it is also a great effect. It was originally sold by Uncle's Puzzles.

Around Christmas Walgreens of CVX (I can't remember which one) puts out a line of puzzles that are great. They are the best made wire puzzles I have found.

The wire puzzles I mentioned are in Walgreens now. I just picked up a few more as backups. They are in the Christmas gift isle.

Daffydoug ...
wonderful, true nostalgia.
Pleased to say, wire puzzles are still "alive and kicking" in the UK.

If you are a "worker" and interact with passers-by, then you might want to try the "loopy loop" button hole puzzle.
Attach it to someone's carrier bag or something as they pass by.
When they come to remove it, they cannot. Unless they cut it off ... "I saw him put that on, now I can't get it off!"

How on earth did that happen?
(put your business card on it)

https://www.youtube.com/watch?v=pvdAu_fXPUg

Thanks, wulfiesmith. That's a fantastic explanation. The in-the-hands version takes the puzzle to a different level.

This is a great store for wire and other kinds of puzzles.

https://www.puzzlemaster.ca/browse/wire/