You're saying that you haven't heard nada, zip, zero from this guy in EIGHT years???
And all this time you maintained and used this trailer on occasion?
Who renewed the registration on this trailer during those 8 years? If you did...how did you do this without it being in your name??
If he did, he continued ownership in the eyes of the state.
Trailer tags are due for renewal in GA every year on the owner's b-day. A pre-printed reg form is mailed to the owner of record and has to either be mailed back in or personally taken to the Tag Office.
The person doing the renewal has to show ID to process the renewal.