Although it's focused on 470s (with demos on a 420 dinghy) and there are things we don't have on a Mirror (like spreaders, chocks & full length top battens), there is, I think, a lot of very useful information in here for Mirror sailors who want to improve (for example the cross sections of a mainsail for light, medium and strong winds and the emphasis on measuring & checking settings).
Here are Jonny's slides from the talk.
As some may know, Jonny McGoven used to race Mirrors.
