Great question. And to be honest, I don't know the definitive answer... although I can tell you what I do:
Reverse Fleckerl (starting LF forward)
1. Heel-Flat
2. Inside Edge of Ball
3. Whole Foot
4. Inside Edge of Ball-Flat
5. Ball
6. Inside Edge of Ball-Flat
Natural Fleckerl (starting with RF forward)
1. Heel-Flat
2. Inside Edge of Ball
3. Whole Foot
4. Inside Edge of Ball-Flat
5. Ball
6. Inside Edge of Ball-Flat
I beleive they say that the lady does not use heel leads on the forward-crossing steps like the man does, but instead uses ball-flat. Even the man's heel lead is pretty subtle.
The N.D.C.A. does sell a Viennese Waltz technical manual for $16 + $5 s&h. I haven't seen it myself, so I have no idea what it's like. For more info, contact Joy Edwards at 703-242-2569. Or perhaps the NDCA has some more info on it on their website at www.ndca.org.
I hope this helps.
Sincerely,
Jonathan Atkinson