Sounds like a great idea, I`d definitely be in favour.
Paperwork is a problem, but some form of validation to prove that we own the watches should suffice. Not sure what format this would take, but going through official valuation channels is costly and doesn`t prove much other than the fact that an individual owns the watch.
I`m probably in a minority but I`m happy accepting the risk of wearing/losing a watch outside the house myself, it's a risk I can minimise by care and sensible behaviour so I`m OK with that.
Theft from the home is the major worry IMO.
Pauul