(It's 1967; no bad on the typo.) That is indeed a significant hurdle to overcome. Or is it? just how difficult is it to withdraw from a treaty? I think it could be as simple as saying "we withdraw from the treaty". (China did sign in 1983, I note.)
On the plus side, Congress did pass the Space Tourism Bill, which is a HUGE step forward. Small steps...
We won't withdraw from the 1967 Treaty. We should. There will be no private development of outer space. The State will not allow it until the State is firmly in charge in the new territory. We won't see it this century or next--it's nearly too late anyway. Seek enjoyment from the particle of land on earth the State allows the citizen to own.