Ok Guys and gals in the end I went for the E5300 at 2.6, I am happy with it certainly no perceptible decrease in performance from D840. One interesting thing I have just discovered, the Windows 7 performance test WEI rating was 3.8 based on the CPUs low rating, which I thought a bit low (but what do I know!), but when I used the Asus automatic overclocking utility in AI suite the CPUs rating went to 6.0 (Maximum 7.9) with which I am very happy.
Next I plan to upgrade this processor to the coming E6500 at 2.93 replace the wifes 3.0 pentium 4 with this E5300.
Any comments would be well received.