Yep, the old welder's trick of using magnets to hold together components
Great idea of the gaffa tape to cover them with the tag! I've been using a sock, but the gaffa tape is more robust.
Yes, these
LARGE rare earth magnets need to be used with a great deal of care. If you are not familiar with these, they literally are like something out of a James Bond movie with how powerful they are, and for being so small, deceptively so. NOT something to let kids play with as they will have no way of controlling them, and these large magnets can literally break bones in fingers if allowed to slam onto steel or even worse another magnet. And they don't let go...
I have a couple of these large magnets, and I don't let my kids play with them. Hell, they scare me these things.
On the plus side, their hold strength is so great, I use smaller ones as part of the detachable mechanism of the secondary mirror in my 12" scope. The secondary takes some effort to remove once it's in place.