Anyway, when asked about Geck he says theirs was broke, and they should of had two, but didn't so they just ending up stripping the one they did have down for parts.
This would obviously mean that Vault City is not a GECK built town and the GECK didn't help them one bit, and that so far as we know, New Arroyo is the only town benefited/created from a GECK.
Now, there is some conflicting info, as some other knobs around VC claim they used their GECK. I believe Randal is one. However, with McClure giving pretty good intel on it, I think that his word can be trusted. Plus he is like the one person in VC who doesn't beg to be shot in the eye.