hello again,
looks like what's happened is that sleep from 5:30-7:30 (ish) has become his morning nap, and then the nap he takes at 9 is his "afternoon" nap, causing the 1pm nap to be a catnap. i think that if you can move everything forward a bit, you can help him drop that feed and then start his day for real around 7-7:30am. here's a link to help get rid of that 5am bottle:
https://babywhispererforums.com/index.php?topic=46907.0you may also need to use a bit of pu/pd to help him learn to go back to sleep and not wake to eat at that time.
once you can drop that, you can aim for a day with naps around 9am, and 1pm (like you have been), but hopefully those will both be the longer ones. you may still need a catnap around 5pm during the transition for a little while.
the other thing that concerns me is that you mention erratic waking... this is usually a sign of hunger, so i wonder if he's not drinking enough out of his bottles during the day. you might want to check out the bottle forum and see if anything sounds familiar there.
HTH a little!