The only way you could make this work would be to make the electronics swappable out of the chassis, to give the object some sort of historical permanence for the owner.
Of course, if you could do that though, then you're not really in the smartwatch business, since it would mean anyone could make compatible wrist-bands.
Conversely - that might not be a bad business to be in.
Well if it comes down to the bands, you just know there will be knockoffs. As for the enclosure itself, Apple seems really proud of their manufacturing process for these things. If the guts of the thing are swappable (even if only by Apple), it might be tough for anybody else to come up with a comparable knockoff.
Of course, if you could do that though, then you're not really in the smartwatch business, since it would mean anyone could make compatible wrist-bands.
Conversely - that might not be a bad business to be in.