When my harmonic balancer went out the Parts person at the local Mercedes dealer told me that they were on the 5th revision for this part (which corresponds to the five part numbers you have listed). I was told that they had 3 in stock, when I went to pick up the part the had a 98 E320 in the bay with a bad harmonic balancer and found out that there 0 in stock (the computer didn't agree to what was on the shelf).
At this point I called Phil from PartsShop and had him send me one (PartsShop pricing was much cheaper).
If you would like to get an idea of how many harmonic balancers were replaced, I would talk to the Parts person and ask how many they sold over the last few years. It would be interesting to find out how many were sold at the dealer that claimed that "none of the harmonic balancers are defective".
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles