Guitarist magazine did a shootout. I struggled to find the original but found a summary of the results:
Marshall 100 watt 1959 SLP full stack (reissue, 60's spec)
Vox AC30 (current, it looked like the fawn colored handwired version)
Fender Hot Rod Deluxe with factory standard appointments
The readings were from low to high for the three contenders, 119.5 db, 124.1 db and 124.6 db.