I too was pondering over which Givi tanklock ring to order for my Fazer 1000 and also noted that they didn't list a fitment on the Givi website. However, I checked the aj sutton website and discovered that the same fuel cap assembly is listed for multiple bikes (as you would expect) that are listed under the BF05 application so I can't see a reason why it wouldn't fit. I've pulled the trigger on one anyway so expect it to arrive later this week. I will then provide an update.
Regards