How do I restore an App purchase older than 90 days?

Hello there, Old_Tonto.

The following Knowledge Base article provides some information on re-downloading in-app purchases:

iTunes Store: About In-App Purchases

http://support.apple.com/kb/HT4009

Particularly:

Redownload an In-App Purchase

If you lose your In-App Purchases because apps were accidentally deleted or you had to restore your device without a backup, you may be able to download some of your purchases again for free. See which types of In-App Purchases you need to purchase again or can redownload for free in the table:

Type	Download for free	Purchase Again
Consumable	X
Non-consumable	X
Non-renewing subscriptions	X
Auto-renewable subscriptions	X

To download an In-App Purchase again, you must download it from within the installed app using the same iTunes Store account name you used for the original In-App Purchase.

Cheers,

Pedro.

I Am looking to redownload apps (not in app purchases as mentioned above) that are older than 90 days. They are not showing up in the updates> purchased section of the App Store on my iPhone.

If they are no longer in your country's store then you won't be able to redownload them (any item can be removed by the content provider at any time); if they are still in the store then check to see if you've hidden them : iTunes Store: Hiding and unhiding purchases - Apple Support

If they aren't in the store then do you have copies of them in the Apps part of your computer's iTunes library and/or on your backup of your downloads/library so that you can sync them back ?