I really think you are safe from asbestos, but after hearing about the "shag" carpet and the space age polymer glu-all resin based goo that is holding that stuff to the dash?

You are safe from asbestos, only the bacteria, mold, and mice doo to worry about (as has been my experience). One car that I tore apart once did have a the jawbone of a small dog - now that was freaky. Then there was the 56 wagon with a 5 foot long snake skin up under the dash.
Honestly, I am not making this up.
About the dash: While most guys here would not recommend this (of course this depends on how far you want to go here) I would say that you need to take the whole thing out. You can unbolt it pretty easily because the attachment points are almost self-explanatory. Do you have any photos of the car to post? How far do you want to go with the interior before you actually try to start the thing?
I would say that there is a good possibility that it only has 30k miles on it. Do not be surprised if the engine block you find in the car is not the same one that came with the car originally. Over half of the parts cars that I have pulled apart have had a Y replacement from later years installed - even things like mismatched heads, rockers, combination of 6 volt/12 volt ignition doo dads, sometimes a real circus of parts (but of course, I do live in West Virginia)
Daniel JessupLancaster, California
aka "The Hot Rod Reverend" 
check out the 1955 Ford Fairlane build at www.hotrodreverend.com