This information on "I'm Sorry, I'll Read That Again" ("ISIRTA") and "Monty Python's Flying Circus" is taken from research I did when writing my books: they are compiled from actual recordings and original scripts and information files, and so are as authentic as you are likely to get (though I wouldn't rule out the odd mistake).
American readers, please note: the term 'series' here equates to 'season' for American shows (where 'series' refers to the entire run); and the dates are in European format (day/month/year).
I'M SORRY, I'LL READ THAT AGAIN
MONTY PYTHON'S FLYING CIRCUS
AT LAST THE 1948 SHOW