hello --
I think I know the auction you are talking about.
if so, this phaser is not from the show.
the auction I saw (lot #90) shows a pic of a phaser
made (probably in the 70's) by Brad Nelson, Ed Miarecki,
or Rich Coyle.
again, the pic I saw shows a TOS phaser but it is not
from the show.
it's well known that Gene R befriended Brad Nelson and
had some of Brad's phasers. he even hired Brad to produce
the phasers for Star Trek Phase II, the second series that was
scrapped to make the Trek movies instead. so my guess is that
if this is from Gene R somehow, it's one of the Brad Nelson
phasers he had.
perhaps it did come from someone from the show's collection
as mentioned, but it's not the real deal. I search 'everyday'
for a real screen used phaser, it's at the very top of my wanted
list

I hope this info helps!
startrekpropguy@hotmail.com