William Donzelli wrote:
   The other minor factor ... solid state diodes
did not happen untill about
 the middle of WWII. 
 Yes, and they sucked anyway. 
 
Just a datapoint I'm aware of: within a few years (late 40's) Whirlwind used
'crystal diodes' in the 'control matrix'.
  Still, if there was enough money behind a computer
project, I bet RCA
 or Sylvania could have been convinced to make a run of diode gating
 tubes using 6H6 elements. 
(There was a triple diode released in the 50s or 60s)