That is a great question. Can't say that I have had the chance to measure them. I'd sure like to know the right answer.
Yes ,according to a FordBarn thread last year. 9 Cool Kat with Hot Car Senior Member Join Date: Jul 2010 Location: NorCal Posts: 288 Re: 1939 Mercury convertible. Common parts with a sedan. rear fenders are the same on coupe, convert., and sedans
I had an early production 39 Merc many years ago number 87 if my memory serves me well. Almost NOTHING fit from later 39 models! I finally ran into an old Ford/Mercury mechanic that explained the anomaly. Henry didn't want the Mercury answer Edsel did. He felt that Ford was breeding owners that wanted to move up would go GM or other makes because Ford had no intermediate car. Henry fought hard to stop Edsel but to no avail. Edsel was so worried about perfection that th3 first hundred or so were completely hand assembled. As I said previously m8ne was on of those. Lots of them carried hub caps lettered "Ford Mercury" to satisfy Henry. I have one of them hanging on my garage wall. A friend of mine bought it for me for $10. It was hanging on a wall in an Oakland hock shop! Since it reads Ford Mercury, it piqued my interest and led me to research the history of "odd ball" hub cap. It does start conversations with people first visiting my garage! It looks like any other wide 5 hub cap, except it has Ford at the top and Mercury at the bottom just above a bead running full circle on the stainless portion.