I agree with what Bcam is saying and I too believe it would be helpful.
I've observed other vBulletin forums that have the "original poster" designation each time the OP posts in that particular thread. Therefore, there must be the option somewhere in the administrator's control panel that "may" allow that to be done on this forum too.
As an example, a very popular and busy forum (City Data) that uses vBulletin software utilizes that feature. Notice where each post by the OP will have this designation?:
An example of a thread from that forum that uses VBulletin software
Can we get you folks to dig into the control panel a little deeper to see if perhaps that particular feature can be used here?
ETA: Disregard ...I now notice that City-Data may no longer use VBulletin. They once did but now I'm not sure as I no longer see evidence of VBulletin on their reference pages.