Ford limos?
An old Collectible Auto article on Ford in the late '30s includes a fact that I haven't seen anywhere else. It seems out of place.
Note the 7-passenger sedans. About 500 of them sold in each year, which counts as mass production. Not just a prototype or a special order for a company executive. DeSoto typically sold about 2500 limos per year in that era, and those are well known.
The text of the article doesn't mention these limos, and there's no indication in the text or the tables that Ford made any long-wheelbase models.