Yes, you can enter both 1098s. However, you can leave the outstanding mortgage principal reported in Box 2 of the mortgage that was sold blank or zero. This will ensure your mortgage limitation, if applicable, isn't skewed (the calculation will add them together).
Box 10 isn't required by the lender but it's helpful. You can add the amounts that were paid into the Box 10 (not the escrowed amounts you paid each month, but the total tax the bank paid on your behalf to the tax collector- check your escrow statements to confirm).
