Just though I'd post the following information for those who don't know yet:
Sturmey Archer Dynohub
Made In England
"8 59"
32 Hole
OLD = 93.00mm
Flange Diameter NDS = 42.00mm [Slotted Paired Holes - 18 Degrees]
Flange Diameter DS = 102.00mm
Offset NDS = 32.00mm
Offset DS = 25.50mm
If you think the NDS holes are simply slotted evenly spaced holes - that is not the case.
The NDS are actually slotted paired holes - much like some of today's boutique paired hole hubs.
For the above noted hub - the degrees for each pair is 18 degrees. When entered into the "PAIR-HOLE-HUB-CHART" tab of the spreadsheet at:
http://www.mrrabbit.net/wheelsbyflemingapplications
The crossing factor for 2 Cross = 2.10 Cross
The crossing factor for 3 Cross = 3.10 Cross
If your Sturmey Archer Dynohub (Vintage Models) is of some other hole count - you'll need to measure the degrees per pair - and enter into the "PAIR-HOLE-HUB-CHART" utility to find out what modified crossing factor you would need when calculation spoke lengths for your particular wheel.
Hope this information is useful for someone working on one of these hubs.
=8-)