Today I started in on the wheels. They're pretty ugly.
I need to determine hub offset. The front was easy as the hub is symmetrical and it's centered on the rim so I didn't need to measure. The rear is also apparently centered, but the hub is asymmetrical, so I decided to measure where it sits. I just laid a straight edge across the hub flange and measured the distance to the rim. Looks like about 3.5/64 or 1.4mm.
The nipples were pretty badly corroded, so I just used the Sawzall to liberate the hubs.
Ever growing pile of cleaned up parts.
I discovered the rims are nice aluminum ones. They look like they'll clean up nicely, so I might just polish them instead of painting. I also found the u-joint was a bit notchy - but I've decided to throw it back in as there is no easy way to replace it, BMW wants you to just get a buy a new drive shaft.