Go to Capitalcycle.com & peruse their Hepco & Becker parts. I found all the parts I needed to convert a Pelican case into a top box there, including a lock cylinder keyed to the ones I already have.
Don't know about international shipping, but it's a starting point.
'04 GS Adv- A fond memory
'07 990 Adventure- still bonding...
How hard can it be?
- Jeremy Clarkson