I first used Steve Lynham in 1981 when he was working out of his home garage in Highworth (Suzuki AP50!!). He did good work then. Took up a ZZR1100 2 years back that the big ends had gone on, and was part dismantled (I got the bike off a mate who couldn't be bothered to sort it). He got a reconned crank, fitted new big end shells, rebuilt the bike and delivered it down to Devizes. Quote was £500. Bill was £500. I can't fault that price for the work involved. I wasn't impressed with one of his youngsters whenever I went there as he was as sullen as hell & unhelpful. But, Steve did a good job and was true to his word, so I'd recommend him.
The other alternative is Marcus at Wayside Garage (01380 860272) nr Devizes. Generally booked up for a few weeks in advance, but good service, and you get the work done by Marcus, or sons Ollie or Tommy (BSB & B Supersport respectively). Marcus used to tune all their race bikes before the Vivaldi sponsorship, so he knows his stuff.