What a fascinating thread.
I have searched for info on these Mack hubs, and I found a detailed photo here:
http://www.velochamp.com/?p=354
I'd really like to see a detailed photo of a single fixed rear hub by Mack.
Since this hub has sealed bearings, I'd ride it in the rain.
For that matter, I'd ride loose ball hubs in the rain.
I remember mihlbach describing this wheel build some time past, and I didn't think it possible.
Thanks to Batavus for sharing, and thanks to mihlbach as well.