The Pro Reverb serves as a nice midway point between the Deluxe and Twin Reverb, having a bigger sonic footprint than the Deluxe, but not overly loud for use with smaller stages. These can be seen as the best deal out of any of the Blackface era amps, and if you're willing to bear a little extra weight the sound is worth it. The speakers have been swapped for period appropriate Oxford 12T6 from 1970. The reverb tank has also been changed to a modern Mojotone, which sounds fantastic.
Internally, it has a replaced power cord and electrolytic caps. A couple of resistors have been swapped for period correct carbon comp types, and most people wouldn't notice the difference, visually. Thankfully, all of the original "Blue Molded" Ajax coupling caps remain, preserving the Blackface sound. See circuit pics for further details.
In terms of condition, the amp looks excellent with very minor signs of previous wear!