These cars only weigh 2700 lbs, There is really not reason to go 5 lug. Plenty of nice wheels. If you rebuild the brakes properly, the stock drums are more then sufficient. I never had a need for disc brakes. These are rare cars and imho should be left stock
Jim, my 62 had air conditioning and no stamps at all in the ACC line.
But a/c could be dealer installed and no way to tell. The assembly line manual outlines the installation, but it would take a lot of work at the dealer to install it.
I just checked the home page that says April 20 was when they were introduced, So if your car is 04B, that’s April, 2nd week for production. Looks like you have one of the first ones so you will have to restore it and not use it for parts! Curious to see how low the body number is.