[Mr70]

To be correct,Locksmiths can't just re-key an original lock to every original GM key,unless they share the same profile opening.
Each year,GM used a different key lock face profile/slot.
You'll have to find a vintage GM lock,with a profile that was also used during your vehicles year.
They alternated their locks every 4 years or so,so it's not that difficult,as you can use a lock that was coded a few years before or after yours was.
Otherwise they can't make em fit your cars original keys,and you'll have to have multiple keys on your keychain.

I have a few NOS sets left in the box,but not sure what years I have right now.