Yes it was. In fact it was derived long before there was even a Watch Tower Bible and Tract Society.
Did the pyramid play a huge part in Russell's belief about the end times?
Not at all!
Was Russell's chronology accurate?
You're asking me? Then I would have to say "yes!"
Was his predictions accurate?
Close! Some of his expectations were not realized, you have to keep in mind that JW chronology and predictions are different from Russell's, apples and oranges as they say!