Maybe I'm the only one that picked up on this but Kim said "I have a
HALF (my capitalization) 750 ml bottle excess that I'd like to use to
top off after the 2nd racking."

I wouldn't store 375 ml of wine in a 750 ml bottle. There will be way
too much air in contact with the wine. What I do is use 2 liter, 1
liter and .5 liter plastic soda bottles. Put the excess wine in an
appropriate sized bottle, squeeze the bottle until there is no head
space, then cap it.

Even if the plastic allows some O2 to go through, it still won't be as
much as a wine bottle only half full.

Andy