Got the bike back today, and credit where it's due i must say that the police, the insurance company, Bennetts, and the recommended workshop, JPS Dyno of Bishops Stortford, were all very professional and communicative in the whole process.
Got plenty of phone calls and reassurances from all parties, and the bike came back better than new. replacing all parts with new. Even got an upgraded seat (form the revised model, apparently)
So. Apart from missing five weeks of riding, all turned out fine in the end