Plexi 100 West Coast mod with the following notable specs

a) Use 6550 tubes, with 2K2 10W screen resistors
b) 12AT7 for PI
c) Higher voltage PT (500V + for B+)
d) 100uF mains filtering total, 100uF screens, 100uF PI, 32/32uF preamp
e) Shared cathode for V1
f) Possible alteration to PI plate resistors and PI tail resistor
g) PPIMV (at the back, in the 1/2 power switch hole)
h) 4700pF bright cap (on push pull switch for ours)
i) 68K NFB resistor into 8 ohm tap
j) 4K primary OT (use JTM100 OT)