I had a T-139 (hence my user name), and it was a great trailer for what it was. The newer ones, X-139, are fiberglass. The T series was aluminum.
The "hatch" in front is, I think, the rock guard -- it is a panel that drops down to cover the window while traveling.
As far as I know, there was no model of the 139 with a sun roof.
And this forum is pretty much the only resource for the older models of the Shadow Cruiser and Fun Finder lines -- we used to have a Yahoo group, but Yahoo made it much harder to use, so a lot of us migrated over here.