[meteorite-list] Udei Station vs. NWA4024 winonaite types

[tett]

List,

When stumbling across an ad for NWA4024 I saw pictures of the meteorite 
and immediately thought how similar it looks to Udei Station.  Comparing 
the pics of NWA4024 and my slices of Udei Station reveal very similar 
compositions.  However, NWA4024 is classiifed as a winonite where as 
Udei Station is classified as an IAB iron.

Further research shows that it is likely Udei Station and other IAB 
irons along with Winonites come from the same parent body.   My question 
is, what is the dividing line between Winonites and IAB's?  How does one 
decide which group the meteorite should fall?  Is it %Fe?

Thanks for any help and

Cheers!

Mike Tettenborn