Hi Barry... just noticed your post. The interior width is the same as the full size queen mattress like you assumed. We are in Spanish Fork with an ill daughter so I can't measure the isle for you. I'm sure someone will post a measurement shortly. I have emailed ETI again Saturday re the height. It looks like they should have them off of the trolleys and could get a number for me if they weren't so busy. We had a couple from Jackson Hole look at our 19 last week before we came down to UT. Their comment was "it's just like new." You would still be first in line if you still have an interest. I would like to see an Oliver in person. They look like a beautiful trailer ($$$). We will be back in Idaho Falls on/about May 16th and 17th if you wanted to see it. I'm still thinking about $30k given the current market for the 19s, the condition of the trailer, and the wait time and price increase for a new one.