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.
'7? Benelli 650S, '80 BMW R100 RS, '07 KTM 990 Adventure