Exactly... and that is the problem with what I have. Copies of copies of copies.
I'm hoping we can get around that with Jeff's magic...
I picked John's to answer, but this applies to all. I do not have the 59-66 blanks John showed above, they are available on EB, but I never found a good price on them. I have some of the 68-70 keys John showed and plenty of the later Pentastar keys. I have code books, which are useless without a code and I have several key gauges. I have Curtis model 14 and model 15 code cutters.
I DO NOT have a working duplicator, though I have an antique hand crank one I could look for a cutting wheel for... it's not a museum piece and I thought it would be neat to play with. Stan is right as far as duplication is concerned.
The issues with the Curtis cutters is the codes I pull off the old key, if it's that bad, may not work. If you don't have the car for the tryout key, I can send you home with the key and send you a pretty one later... it would avoid killing off my limited resources.
If I thought it would be at all practical, I would go for a locksmith license and buy them in bulk (the later Pentastar key blanks are still in production), but the only way I've found to buy them at a decent price is through a wholesaler that requires a license.
I do have too much of this stuff, so I am willing to help out anyone in the membership who is interested. I have lots of pins too, but I wouldn't bet your functioning lock cylinder on being able to restake the pin cover, If you have an unmatched spare... we could try to pin it to your key of choice.
Buy new tumblers and keys.
There are some on EB that are extremely cheap, repops I'm sure... but it's all good if work and look right.