MartinMikey,,, If you havent drilled it out yet, I have a string of about 50 or so G.M. ignition keys. One of them is SURE to fit.
If you promise (stovebolter promise) to send them back to me,,i'll send it to you and you can go thru them till you find one to fit.
Youre more than welcome to try it but, I HAVE to have it back.
OR,,,, If you want to send me your old lock cylinder and new key tumbler part,,,I'll switch them for you. No $$ involved.
Marty