Did " The Sinister Omen" start off as a Hardy Boys book?

[Bigfootman]

I was reading the blog "Series Book for Girls" when I found this article:
https://series-books.blogspot.ca/2016/05/comparing-nancy-drew-and-hardy-boys.html
I'd highly recommend reading the whole thing, but I'll quote the relevant part here.
"I believe that the Stratemeyer Syndicate had to scramble to try to keep up with the Nancy Drew series after Harriet's death.  Some Nancy Drew Wanderer books were apparently rewritten from what would have been Hardy Boys books.  Nancy Drew #64 Captive Witness reads like a Hardy Boys book, and Nancy actually acts like a boy and not like herself.

Nancy Drew #67 The Sinister Omen also reads like a Hardy Boys book, and Nancy even rescues her father from imprisonment just like the Hardys would have done with Fenton. Not only that, but in the first Wanderer printing of The Sinister Omen, Carson is actually called "Fenton" on page 79 and "Mr. Hardy" on page 84.  Last, Nancy Drew #75 The Emerald-Eyed Cat Mystery mentions Bayport!  It looks like three Hardy Boys books were changed into Nancy Drew books during the Wanderer era!"

I  have the first printing of the Sinister Omen, and here are the quotes mentioned:
Page 79: "I found out that you were relocated, Fenton,"
Page 84: "The losses now are running towards the billion-dollar mark," Mr. Hardy said,"

I should also note that Captive Witness and The Sinister Omen both had the same ghostwriter, Richard Ballad.

[CalvinKnox]

! That's quite something, I have a Wanderer "Sinister Omen", I'll have to take a look at it.  I'm not a big Nancy Drew reader, but "Sinister Omen" is the only one were I remember her flying an airplane.  I read "Captive Witness" about 15 years ago, but don't remember much about it except for something about the Iron curtain.