Not trying to take this too far off-topic, so will keep it short. As stated above, took the radio box off a KZ1000P, sanded, taped, and primed. You can see - it is kind of square.
In photo two you can see that even the Navy was not near dark enough, and unfortunately, this was the darkest blue I could find. So I resanded and then went with the hammered black as my alternative. Paint turned out okay, but in no way matched the lines of the bike, so I added diagonal reflective tape and an oval reflector. Mounted like Mike, 4 holes with the m6 - 28 x 30mm bolt with philips head and spacers to between the box and the rails. It is very solid, but not terribly elegant. I won't keep it on all the time, but for long trips is will help. AND it cost a total of $28 for paint, bolts, and tape.
Sorry, it was dark and dreary today, so last photo not great from my phone.