In searching for the link I just posted in re ignition switch, I came across several threads where people had lost keys and were frantically trying to get replacements without the rather large expense and hassle of changing locks.

Something I started doing several cars ago is recording the key codes, VIN, license plate number, anything else you might need some time and emailing it to myself. That way I can pull it up from my email archives when I need it, and from any computer.

I've been away from Corvettes for a few years; just got a '90 and when I did the email for it I even copied the SPID sticker from the console lid. Now if I wonder what rear end it has, for example, I can look there and not even have to go outside. Did I mention I've gotten lazy in my old age?

I spent some time as a locksmith and will be happy to tell you how to decode your keys while you have them. Then, if you should ever need a replacement, any competent locksmith can cut a replacement from the code, or any GM dealer---doesn't even have to be Chevrolet---can as well. Dealers are pretty **** about wanting proof of ownership first, and they're a bit pricey, but any port in a storm.

Meantime, if you don't know how to decode your keys, take a picture of them. Get as close as you can and get both sides. That isn't quite as precise, but would be a giant head start over nothing. You can also trace them with a pencil.

If you know how to use an ohm meter, measure the resistance of the VATS slug in the ignition key and cross it to the chart found here:
http://www.vatskey.com/vats/lostvatskey.htm
and make a note of that number. Your measurement will not likely be exact, but should be very close to one of those numbers.

Maybe I'll sit down and write a little treatise on how to decode the keys with a dial caliper; nearly everyone has one. I reckon it would be worthwhile if it saved just one guy the grief of having to start from scratch.