Heya mate,
Good news, albeit slightly different! Had a dig through the spares box tonight and managed to find an unused 185mm rotor for you.
It's still yours for the same deal, as it's not even G2CS, but the older Roundagon style. I must have got them when I had BB7s, but I never used it!
Photo attached, PM me your details if you want me to send it up!.