Good point about the actual geometry of the bearing surfaces. I think making sure the LOD is the same is probably in order. Good point about exposure to the elements too. The non-drive side has one of those tacky coned shaped rubber gaskets you see on Shimano hubs and the drive side has....well....nuthin keeping the grit out except it has to get past the gear cluster and all. It hasn't posed a problem so far.

Thanks for all the suggestions.