"Potential" branding is worthless. Nobody looks at domains when trying to think of a brand name. They think of the brand name first, then they buy the domain. Not ot say it couldn't happen, but with that domain, it certainly is a long-shot.
As it stands, it is worth nothing. In fact, you would have to pay me to put that one in my portfolio. No offense.
I do not recall G66 actually meaning anything, but then, i do live under a rock sometimes. If G66 is a popular term amongst a certain crowd, please let us know. that can make all the difference in the world when appraising a domain.