Yes, that one, or one of it's earlier incarnations. The "Executive" came in Model A, Model B, Model C, and the picture you have there is a Model D. BTW, I'm learning as I go on this, not a typewriter expert by any stretch! I did find a website that has manuals for these typewriters, but so far haven't found any material that conclusively shows availability of a "superscript th" character.
However, based on comments from credible folks here, who have personal experience, I am inclined to think that such a character was available. I don't take either the proportional spacing or the "superscript th" as conclusive evidence of forgery.
