Unable to sync full 'Photos' album in iTunes

Since updating to OSX 10.10.3, I am no longer able to fully sync my albums in Photos to my iPhone 6 via iTunes (12.1.2.27)

I have an album in Photos titled iPhone 3G/4. It contains all of the photos I shot on my previous iphones. The album totals 7,522 (about 9GB of photos) items in all.

When I sync to my iPhone in iTunes, and choose sync only selected albums in Photos, and choose this album (this is the only album I am selecting), only 1,118 photos sync to my phone. I have a 128GB iPhone 6 running iOS 8.3. I have used 49.3GB, and have 65GB free to use.

I have tried the following solves with no success

deleted the iPod Photo cache in the Photos library

deleted all other albums in Photos so that the only album/collection is the iphotos 3G/4 photo

unsyncing and re-synced my phone several times

Can anyone recommend anything else to get these photos back on my phone? My hope is the solution does not involve wiping my phone and setting up as new. I have several apps on my phone with data that I cannot bear to lose, and since there is no way to add apps back to your phone with data a la carte, I am stuck. I never had issues with this type of sync in iPhoto, this is a problem that seems to be unique to Photos.