If you bought Entrenchment and Diplomacy separately, you should have an account with GameStop (they bought Impulse a couple of years ago) which you can use to download via the app formerly known as Impulse. It will probably be the same account/email address as you're using here, since yours dates to 2008.
If you have any trouble getting the registrations to show up there, contact [email protected] and they should be able to provide an alternative.
