Sorry to see this occur to you, but it is very common and I can show you 4-5 cracked wheel centers. We ran these wheels on the RSR 993's. You *should* have caught this WAY before catostrophic failure
People ask me all the time why we clean our wheels after every session.
Cant see the hairline cracks in wheels when they are dirty.
I know of a few people who might have some good centers.
I personally would suggest you not run these and move to the newer version they released later that is full CNC and lighter. They are easy to spot. The spokes are much thinner where they machined them out.
B