This excellent-sounding Blackface-era Princeton Reverb has a few minor updates but remains original where it counts. 
The baffle has been swapped for a 12" style—widely considered an upgrade and a common mod on both vintage and modern Princeton amps. It houses a true gem of a speaker: a 1960s Vox-labeled Silver Bell Celestion T1088 with its original Pulsonic cone! This same speaker type was used in vintage AC-30s and is worth around $500 on its own. It sounds absolutely angelic. As expected, the amp now projects a bit louder and carries a more commanding sonic footprint. Also, the original baffle is included for the next owner.
Internally, it retains its original power transformer, which has been re-wound by Heyboer. They replicated the exact winding ratio, and since it only handles voltage, it performs electronically identical to the original. The amp also has an updated power cord, fuse holder, and fresh electrolytic caps, taking care of it's “100,000-mile maintenance.” One plate resistor has been replaced with a modern carbon comp equivalent, but all other components remain original, including the iconic “Blue Molded” Ajax coupling capacitors. 
In short, this is a high-performance vintage amplifier with all the maintenance you'd want, along with a legendary British speaker!