Some metal case Sistem51 models since 2016 have had removable casebacks, so serviceable models have been around for a while. The older plastic models were not serviceable.

This site claims that Swatch told them the FF case back was removable.

Supposedly the FF is glued to be able to get to the “50 fathoms” depth rating, probably it’s less a less expensive/complicated option compared to a screw-down back (the indentations on the case back look decorative, I don’t think they’re deep enough to survive being gripped by a tool). FWIW, Fratello’s blog post quotes Omega’s VP of Product as saying the case back can’t be removed, but I’m not sure how reliable the source is given the supposed statement from Swatch that it can be removed. To reconcile these two statements, I’d speculate that the Omega VP is erroneously applying the MoonSwatch’s reality to the FF, but who knows…

The case back on the FF Swatch is glued, not integral to the case, so you shouldn’t need to destroy anything to remove it.

You can just swap the whole movement out.

Are you sure he didn’t gift you those watches?

Collecting is more about mindset and intent than anything else. My wife has multiple watches, but it’s not a collection because she doesn’t intend it to be a collection. I have a bunch of suits to wear for work, but I don’t consider it a collection. The three-watch collection is a recognized trope, and the one-brand variant is a much-discussed variation. If that’s what you consider yourself to have, then you’re a collector.

Underrated by people who aren’t into watches