I sent photos to a Bike shop in Canada and here is their reply concerning the AD bottom bracket threading: "It is possible that the Austro-Daimler has Swiss thread (35 mm L & R hand threading) but it could be standard English (1.370" L & R hand) or French (35 mm R & R hand). If it is the original Nervar b/b set the knurling on the lockring edge should tell you what thread it is. If it is English the knurling will be a cross hatch but if it is French it will be a straight knurl across the edge. If it is Swiss the adjustable cup and lock ring will be the same as French but the fixed (RH) cup will have a LH thread. You will only be able to determine that by unscrewing it... the knurling on the b/b lockring appears to be straight across which would suggest French (or Swiss) thread."
I think that I will attempt to only swap the crankset on my AD. Looks like the Suntour Cyclone 7000 may be a fit.
The brake upgrade will take some study, somewhere in my reading, I recall seeing a comment about using two front brakes with the recessed mount design for older frames to deal with the rear hole access problem. Anyone know if this works?