Ok so here is the sequence of events:

iphone 3g bought and used for a while
backed up
sold/traded

iphone 3gs bought and used for a while
restored from backup of 3g which had all my contacts, notes and photos(i dont really care about the photos just wanted the contacts and notes back)

3gs came with FW 4.0.1 when i bought it, luckily the previous owner had cached the shsh blob so i was able to go back to 4.0 but nothing previous

downgraded to 4.0 with intent to jailbreak(still waiting...) and when restored, chose to set up as new iphone(renamed Dev Phone because i wanted to tinker with it and i dont really know why I called it that but it doesnt really matter)

decided to clean up itunes by deleting old backups except most recent one from the 3G i previously had.

latest backup still present since i backed up before restoring 3gs so now that backup is the 3gs's backup of the info that was on the 3g so its current.

for some reason itunes won't recognize that backup so i created another backup and then i closed itunes, went into the library/application support/mobilesync/backup folder and changed the name of the new backup to the old one and renamed the old one .bak just in case i wanted to revert.

itunes still wont recognize it. so my question is, how do i get the old info from the important backup to show up in itunes so i can restore to that backup and then just manually update any fields that have changed(i think i have maybe 3 people's contact info to just change phone numbers in and i have those written down so i'm good on that).