Lucy-Desi hour and FRED MERTZ

I got my DVD's... I was watching the episode
with Tallulah  Bankhead..in the early part of it,
Lucy calls Fred "Fritz".  I remember that she
called him that in the Ernie Kovacs episode too.
I'm trying to find if those were bloopers were maybe
Fritz was a nick-name for William  Frawley.  I don't
remember Lucy every calling him that in the 179
I Love Lucy episodes.   The search is on !!