bombertest1

hi
1)You dont need to arrange the pcc's again from pakistan. You and your wife will only need to submit pcc of saudi arabia. Your sons pcc would be required from watever place they have lived after attaing the age of 16.
2) No, you wil not need to sumbmit AOS again.
Everything embassy requires will be asked in interview letter.Wait for it.
No one can tell you the exact time for your PD to be current. At current pace it would be current at approx. Oct-Nov 2014.
Wait for 12 weeks; then u can e-mail them.

The time your petition was pending is almost 7 years 8 months and if you subtract that age from son's present age he can qualify for visa as it comes under 21 i.e he's not aged out yet. Without any delay write a email to NVC stating that CSPA applies to the case and wait for their response.You can also call them and inquire the same.

I am also CSPA eligible candidate and by hearing "US Military Selective Service", I got shocked.
Thanks Waleed39 for your explanation.