You don't state where in the world you are living or plan on selling prints. Every country has different laws. The fact that the car is from 1947 is irrelevant.
The laws of the country you're in may be irrelevant, too. When you purchased the ticket for the museum, was their anything on the ticket that addressed photography on museum grounds? When you buy a ticket, you are actually agreeing to a contract. This is how the museum could skirt local laws.
It is possible for the museum to own copyrights on the cars within their collection. Of course, this fact would not necessarily be printed on a ticket or even shown anywhere in the museum. If the museum or its owners have copyrights on the cars, then you cannot sell the image for commercial purposes. However, fine art does not legally fall into the category of commercial work. This is why, in the U.S. for example, you can't take a photo of someone on the street and use it for an ad campaign, but you can use that same exact image for fine art prints and sell a million copies.
So if you're in the United States, and the museum or its owners do not have any copyrights on their cars, then yes, you can make and sell prints. Even if you had the brand name in the photo, you would be able to sell prints as fine art. But, if you wanted to use that image with visible branding in an ad or to promote some kind of business in any way, then you would not be able to do that without expressed written consent from the owner of that brand.