Well, the rear light surround has proved elusive in the two years I've owned my 851, so I finally plunked down for a replica... and it's pretty decent! It's a slightly flexible plastic and when it arrived I thought it was warped but cleverly it straightens out perfectly when bolted up. Looks indistinguishable from a couple of feet away. Hurray! I did the decent thing and ordered two of them... the last two I believe from a passion project of a contact I have in Perugia. If anyone is stuck for the same then feel welcome to PM me. They were not cheap, but as the only one I've seen come up in the last two years was imperfect and almost £300 (!), this was money well spent at £150 (for a bit of plastic... jeez). Having repaired the original twice now and had it re-break (vibration while riding I assume) this more flexible one could be just the ticket. Bring on the good weather!