One thing I found out about the missing Bf109 claim, is that he never filed claims for victories.
Frank Olynyk lists three combat reports with claims by Overstreet, all backed up with credits from their respective Victory Credit Board (VCB) reports.
He did file claims.
I don't know the details of the Eiffel tower incident and haven't had time to hear what the man himself says in the interview. If he did pursue a Bf 109 under the Eiffel tower and subsequently destroy it he didn't file a combat report to be reviewed by the VCB for that one for some reason.
I'll just stick to the known facts and sit on the fence
Cheers
Steve