I called Lance today and did not get much to answer my questions. The folks I worked with tried to research if the windows were interchangeable, but no luck.
Getting a schematic showing the window openings would probably be helpful. I did not ask for one. I got schematics for some of the areas of my 1121 years ago, so maybe I can get them.
The issue at this point is that I have no specific model, other than an 1181 or 1191, and no specific year. I am not really excited in buying one with the sliders until I can pretty much determine they can be changed out.
On another, but related note is that I am currently looking at an 1181 with the correct windows. It's just on the other end of the country.
Thanks for all the input, it may still be useful.
Dale