The description says the right is 30mm closer to the bike than the left, which is the difference in width of the e45 and e36 case. Seems accurate to me.
http://www.amotostuff.com/super_tenere_luggage/PLR367.html
This probably doesn't show it very well but there is a 36 on the left and a 45 on the right. 45 on top.
Plugugly, this isn't a great shot but hopefully it tells you what you want to know.
In keeping in the spirit of "what I did to my Tenere today", I rode down to Carson City to Adventure Motostuff (link above) and bought these three cases and a new lockset so I can key them all alike. Nice shop, lots of inventory. I talked with the owner and she confirmed that if their website says "on hand" then it's in their shop. They let me try the boxes on the bike before I bought them. Unfortunately they aren't open on weekends. I guess most of their business is via the web. Still, they have a nice showroom.
The two e45 cases came in the same box and were keyed alike from the factory. The 36 was different though so I had to buy a 3 lock set to get them all the same.
Here is a hawk I saw eating lunch when I stopped to take some pictures of the bike.