Seems like you could have a pilot bearing sleeve made up like the Mopar unit, but with a nose on it to support the OEM Toyota roller bearing. Ought to be easy work for any machine shop, especially if you have the Mopar bearing/sleeve to use as a go-by.
I guess you could mill the bellhousing as long as there is sufficient material there to support the loads after the job. I'm not a materials guy, so I don't know what the possibilities of that option really are.
Sure looks like you're making some good progress, though. I need to get some more info on my swap in the near future. The last few months have been nothing but parts chasing...
