I searched but couldn't find definitive info on the center faces for Style 5 wheels in the 17" variety. BMW made many versions of style 5s in different widths and offsets (for both 17" and 18" diameters)

E34, E32, E31 72.56 hub bore:
-17X8 ET 10
-17X8 ET 20
-17X9 ET 22
-17X9 ET 26
-17X9 ET 19

E39 74.1 hub bore:
-17X8 ET20
-17X9 ET27

I'm trying to figure out if all the 17" style 5s centers are the same for all the above wheels regardless of wheel width and offset (besides the hub bore diameter). As in the hub face to back of the bolt flange distance, and bolt flange thickness?

Eventually I want to build a set of custom style 5's using the 17" centers and custom barrel and outer step lip to 18" diameter. If the centers are in fact different for the various 17" style 5's then I need to accommodate for this in terms of the barrel width and lip width that I choose. Ideally I want to end up with an 18X8.5 wheel, ~ET13 offset.