Okay an update.

I called the EXP line before the itin had been ticketed. The EXP agent wanted to reprice the whole itin, from which I asked why and she confirmed because it had not yet been ticketed. I asked if I waited for it to be ticketed would they be able to keep the outbound fare codes, from which she said yes.

So waited for the email ping of the eTicket being ticketed.

Called 2nd EXP agent, stayed on the phone for nearly 50 mins, as she went through different options, but all of them resulted in her being able to keep the outbound fare code, but could not get a cheap return. Checking on expertflyer there was plently of M, S and V fare codes available which she confirmed but could not get the fare pricing to be sensible. She offered later flight with same routing and it would be confirmed at $400 and no change fee which was a partial win.

I asked one last time if there was a routing that would reduce the overall, she went away and came back saying the change which was previously offered at $400, could be offered at no additional cost and no change fee..

RESULT.

BM