Very, very nice! I always loved that obelisk! It's one of the most interesting props built for the series. A lot of fans joke about the tighter budget for the third season, but it seems they went "all out" for this episode. I'm guessing the prop had to be "destroyed" since it was a location piece, but they could have, in theory, saved the panels with the raised inscriptions for a later story.
Had the series run a fourth season, they could have built upon the mythology of the "Preservers". But in 1970, I guess they would have still structured the episodes to be more or less independent, no "story arcs" which are the norm today.
Vue really gives a level of realism to the scene!
Sincerely,
Bill