Graphix FX

So, I am going to look at a 46 Limo on saturday. I have a couple of questions. I am not new to old cars, but I am new to desoto. First off what is availability of parts for something like this? Also, how can I tell what I am getting? How do I know it is a limo and not something else? This car appears to be in great shape for a sixty y/o car. Never restored, owned by a funeral home. less that 100k miles. no rust through. This all sounds good, but just don't know much about the desoto marque. Thanks in advance, and hopfully I will be adding a 46 desoto to my cars.