Blue:
I think Jimmy is doing a CR replica, or something similar.
For what it's worth, there's nothing all that wrong with drums. I've ridden properly set up 4LS's on a few Manx that would surprise you.
An AP Lockheed expert has been quoted as saying, "Every thing you can do with a disk you can do cheaper and easier with a drum". The one place he saw a real need for disk brakes was racing as they are less prone to fade. For road use it isn't an issue, and with adequate cooling isn't really much of an issue in classic racing either.
When disk brakes became the norm for roadracers, the privateer machines generally retained drum brakes. This may have something to do with the vastly increased 'feel' you get with a cable operated drum compared to the "woodenness" of early disks.