Hi Keith. A reflector! I think I did look at that on EB, nice photos, and I think it could be a older model with the serial plate on the OTA and mount.

Ask the seller if he could look at the numbers stamped around the drive motor, that will give you a date if it's original which it probably is.

RV-6's are great, better than the Edmund 6"f8 and you know for me to say that means it is REALLY good!

No doubt has a UPCO mirror (same as the Edmund) they hold up well over the decades but you could ask him to shine a light thru it to see if it is getting thin.

Thats a real classic, good luck.

Robert