Have you weighed yours? I had a weigh of a project one one and it was comfortably above 1kg. Looked fantastic though and they ride very well, much better than the FS variant! Guess it was all that bright yellow paint!
Mine's not an SL, and certainly isn't light! 1311g IIRC with headset/seatclamp/armour etc.
The 9.9s I thought were all guaranteed to be under 900g, obviously not!