I understood that the gov.uk pension site did take the contracting out into account - I think it did with my forecast today. Someone with 35 years of NI (contracted out) will get £119 on the old system which is more that the £70 or less one would be entitled to under the new scheme. These two figures are then compared and the higher figure is the starting amount. I got the terminology wrong earlier as the higher of the two calculations is called the pension "Starting Amount" and not the "foundation Amount" as it was previously known as. Any additional years of NI accrued in future under the new scheme get added to the "starting amount" at a rate of about £4.40 per week per year of NI paid.
One thing is sure, the new scheme is going to be fiendishly complicated for a few years. I have yet to meet a politician who understands it fully.