Over the last few months I've never found myself a good aircooled mechanic I totally trust with my bus (North Gloucestershire, if you know anyone!). After spending a few £hundred on the last repair the mechanic did own up to 'not really liking working on aircooled' Great, thanks, you could have told me that a little earlier!
My Christmas present was a day-long course at Type 2 Detectives, near Cambridge. T2D Bootcamps are very visible in the VW mags and they also feature a lot at shows. According to the site the course covers all the basics on aircooled engines, from electrics to oil leaks, and the most common reasons for breakdown.
It's a bit of a trek over there as you have to go through the roundabout hell of Milton Keynes.... but it looks well worth it.
You can read more about the T2D BootCamps of their website.