Why don't you pose this question over on the DVC community board? Someone there will be able to help. I booked the 4 day Wonder 11 months out and didn't have a problem. I also didn't have a big choice of staterooms.
I booked 11 months out last year with points, no problems but did not have much of a choice on staterooms. I don't think you'll be able to convert a cash reservation to a point one. Good luck.
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