Yes Arthur, from the outer face where the wheel makes contact. You can run a narrow tape measure through the large hole in the flange to get an accurate measurment. How many splines do the 4.5 axles have.

Interestingly, I spoke with Gernold Nisius about my axles. He tells me that many if not most used axles are bent. He didn't seem to bothered by the readings I got, but I have been chasing a high speed vibration for many years and with the flange runout I am seeing, the tire runout is well beyond M-B specs. So, we will see. I really do drive my SL very hard and as fast as I can get away with, so the vibration is an important issue for me. I hope she runs as smooth as it did before this all started.