Here is a photo of my current wheel from the bike, the axle flat extends 1mm beyond the cassette lock nut:



And the brake side, the flat extends 15mm beyond the brake rotor mounting flange:



So here's what the Oval wheel looks like with a cassette installed. Note that it extends 4.5mm out from the lock nut:



So 4.5 - 3.5 = 1.0 mm. That should match the stock wheel. And then the brake side where the end extends out 18.5mm:



So removing 3.5mm leave 15mm which also matches the stock wheel.

Thoughts?