Just for fun, I sent my pics to Roadtrek Service for their take on it.
They (pretty adamantly) said it's NOT one of theirs. They estimated
it was a mid-90s GMC (Vandura possibly), and they didn't ever use GMC
vans, just Dodge and Chevrolet branded. They also offered the theory that
it might be an LT or PW with the Roadtrek decals somehow obtained and
applied. They said Roadtrek always had 3 windows up top, too.
It may be hard to tell from my pics, but this one wasn't exactly in
pristine condition. Maybe it's the one you saw Mark?
Like I said, Imitated, but poorly duplicated....