Both were released theatrically in outside the U.S. You can see plenty of the posters on Ebay, including a couple weird ones. The one with a Han Solo lookalike in place of Wilford Brimley is my favorite.

I'm guessing open matte or 1.66:1. (They would have shot with tv framing marks in the viewfinder either way.) That rather huge book on ILM had a section on the FX work, so there might be a clue in that.

John Korty and directing brothers Jim and Ken Wheat are still active in the industry. Maybe someone could ask them what the aspect ratios were?