Call your local OLD locksmith or GM dealer and ask if they can cut the 1935-66 GM 4-digit code keys. I got luck here about 15 years ago, the locksmith took my code and two minutes later handed me a key that worked. It cost about $5 back then!
If you search ePay with "Old-Vintage-GM-Keys by Code Number-Chevy-Buick-Olds-New" you will find a vendor that cuts keys to order for about $15. Looks like he's had over 5000 sales...
Mike B
