Thanks for the input
So I think I'll just let it ride - closer to the time I'll see if I have time to do a mileage run to IST (LHR-IST-LHR-CAI), or just a tier point hop via another mainland europe stopoff before collecting next years AONEx. I may as well pay the $75 when I know what I want to do.
It's just a real p!sser that I'm ticketed two days before this comes out.
BTW - my last re-route I did at the ticket desk at LHR T1 Domestic, to drop LHR-IST-LHR-CAI and route MAN-CDG-LHR-CAI, as I had no time for the IST run. I was only charged the $75, and no ticketing fee. The desk (who weren't familiar with RTWs) were happy to accept that the $75 included all fees.
MAN wouldn't touch the ticket - even when I offered to leave it with them!