Thanks, Eric. I knew they appeared too close for my comfort. I've seen a number of these over the years with all being sold as authentic. Each letter I have seen is different in text. I'm sure that some others who had seen these up close could tell me if the signature is stamped or autopenned.
Here is another one currently being offered eBay. Note the same signature.
With a $400 minimum opening bid I might add.
Saw this same signature pattern on a signed letter for sale recently. This one was from May 28, 1964. It seems she was using this autopen for at least two years.