Givi seem to be made to fit to 2 basic types of rack.
One for bikes and one for scooters
The bike rack is larger in size.


(Fig1) Locking point plus 2 finger type bars
mainly for bikes (bigger boxes)



(Fig 2)Locking point plus slotted rack length bar
for scooters (smaller boxes)
.

If your monolock topbox comes with a
UNIVERSAL FITTING PLATE. you can
fit this to any rack that has spaces inbetween 
the rack to fit the bolts to retain top box.

IF you already have a monokey rack fitted to your bike
the universal plate can still fit, just note that that the
Locking point on Fig 1rear of rack (IF Metal)!
unscrews underneath with small allen keys.
This leaves you with a flatter rack area and allows the fitting of a
universal plate to the existing rack to fit the other type (Monolock) of box


This allowed me to fit a Fig 2 type box to my wingrack that had a
fig 1 type rack attatched.
I now have a top box that was availble at a good price locally
attatched to my monokey rack via a universal plate (fig 2).

I now have the option of leaving it as it is or looking for a Monokey top box
at the right price/location and selling my monolock box to help pay for it.

thats a win/win in my eyes.

Copy and paste link into address bar for the GIVI website.
http://www.givi.co.uk/caschi_borse_bauli_accessori.asp?cat=107&lang=en

Thank you for looking