Appreciate that those who showed an initial interest have either already treated their bikes and/or don’t want to wait til December - fair enough, my bad for not getting it nailed down quickly enough. Will be all sorted for next year though! 
Thanks for the heads up Rusty, glad you arranged something fairly close to where you live. Once my boss has had his bike done on Sunday, I will post about what he thinks of it, but if there is little interest by Monday I will cancel the dates and just make my own arrangements to go to one of his events around the M25.
Sorry again that we weren’t able to get this sorted earlier, hadn’t appreciated the ‘challenges’ it would represent! A good learning experience.