I agree with Bob Hoffman's comment on this. Attached are two pictures of a 1940 LaSalle Series 52 convertible, owned by one of my friends. The 1940 LaSalle 52 Series has the headlights in the fenders and has a torpedo body. All 1940 LaSalles (Series 50 & 52) have the headlights in the fenders. The body of the 1940 LaSalle Series 50 does not have the torpedo body and is about the same as the 1939 Series 50, other than the headlight location, grilles and other minor details. See www.fzoldcars.com
for many restoration pictures of my 1939 LaSalle Series 50 convertible.
You will want to determine which series you are looking at for later use, as most everything on the body and interior is different. I did not get photos of the inside of this car, but may be going to PA next week and if my friend is home, I will see if I can take some interior pictures for reference.
(Corrected above copy to reflect that all 1940 LaSalles have headlights in the fenders).