I flew with Singapore airlines and was 35kilos over...( this was on top of the 40kilos allowance each) ... the check in girl said I would be charged for excess baggage, but then went & spoke to her supervisor, came back & told me that they would allow it to go through!!!
I was in tears as I checked in, which was down to saying goodbye to everyone.. maybe she felt sorry for me!!!
Have you got anyone taking you to the airport who could get it sent to you if they wont let it through??? Not sure how difficult this would be but maybe worth taking a chance to see if they let it through and have a back up plan (packed case of things you dont need urgently that could be shipped??)