Best of luck to you, I was actually in your exact same boat last year, looking for an E weight rotor and S5 housing, I ended up sending a rotor I bought (S5 E weight) to Mike at https://www.facebook.com/RotaryScience/ to machine mine for 3mm apex seals to match my other. If I remember correctly he happened to have the exact same one on hand that was already machined and I ended up just getting that from him so he could keep the unmachined one. if you're lucky he may still have it and you can be slightly closer on your journey of having a complete assembly!