First of all, to account for the improvement of the replacement part of the present value is how much, the part of the improvement can not be calculated on the basis of 1.5 million dollars, should be based on the proportion of depreciation and impairment after the calculation. The current actual value of fixed assets = 2000-600-300 = 1,100, then the present value of the improved part = 1,100/2000*150 = 82.50, which is the part of the improvement being replaced.
So, the recorded value of the improvement = 1100+500-82.50 = 1517.50 cents.