AC100 serial number 682, conforming to the "100W Amplifier" schematic. A few changes here and there but all reversible. The amp still has its original yellow-print Mullard XF3 EL34s - date codes B5Ex = Blackburn Factory, May 1965, the last digit, which gives the week, illegible.

Other date codes are hard to make out, except for the choke, which has "EW" = May 1965.