Must have new keys.

Removed door handle on my '88 and found the a 4 digit number  on the little
fork that attaches to the end of the tumbler. That's the only number I see
except for the handle part number.

Locksmith says that 4 digit number is not enough. Should have at least one
letter to designate year or he can't find the right key blank and cutting
profile in his computer.

What say The List. I need your collective wisdom.

Thanks,

John