Restoring text messages from older backup without losing new messages

Iphone13, iOS 18.5

For reasons unknown, I've lost hundreds of texts sent to myself, and lost at least one entire conversation. They are not in 'recently deleted'. I'm not backing up to iCloud. I have an iTunes backup that's 2 months old that has the missing texts. I've read that restoring will lose all messages sent after the backup was made.

I'm wondering....If I restored from the older backup to another phone and then enabled iCloud messages on both phones, will iCloud then capture the old and new messages ?

And if I then turned off iCloud, would old & new messages be downloaded to my phone ?

Thank you for your time.