Should I be trying to replicate the NEAS results?

[NEAS: This is an independent student project. The NEAS postings are suggestions to get you started. You can construct an ARIMA model, compare two or more models for a given era, compare two or three eras by type of model of by model parameters, examine seasonality, test out-of-sample forecasts, and many other items.]

No, you can use Box-Pierce for the first differenced stationary series.  If you look at page 496 of the text it gives you the formula for the Box-Pierce statistic.  You know T and if you know the autocorrellations (of the first difference) then you can calculate it pretty easily I think.  There may be another format of this formula using residuals.  I did not use the Durbin Watson statistic for that part. 

Later in the project when I had residuals I used all three to test the series.