I found the following letter in my collection of Corvette News stuff years ago I have the original and noted on a photocopy that I had found this letter in a Dec/Jan 1969 issue of Corvette News. The letter has an embossed Chevy bowtie at the very top and this leads me to think it is probably the real deal. It did not show up in this scan of the original. The letter only mentions the ID card.
Before I posted this, I ran the name and address to see if Joe Jiblets still lives in Maryland and got no results.