OOOO.... finesse.

Jim, I'm kind of a gorilla at heart!! That' s sorta delicate. Didja use the scroll saw blade technique to the get the stub out?

A broken, fine pitch (24 to 30 tpi or so), scroll saw plane can be inserted in the lock as if cutting on the pull stroke, can be used to tease the stub out by sliding the blade in along the side of the key and just tease the stub out using a light rotational motion of the blade to get the teeth to grip the stub. If you can get this down to a "tease the stud out" sort of efficiency, great. If it takes little practice so be it.

Look at the new key it should be a 4 pin design. The outermost pin centers about .080 from the sharp 90 degree cut that defined the base of the grip of the key (See Ron's link below) you can shorten the stub as long as you don't obliterate the outermost pin notch. That will then give you as much as a .070 or .080 purchase to get a screwdriver into the lock cylinder to turn it. If the lock cylinder gets scraped up thatcan be corrected with a new cylinder and key set. Once you can turn the lock to ON, you are home free. From here check out Ron Kwas' article on Volvo 122 keys and lock cylinder removal, etc.

http://www.intelab.com/swem/service%20notes.htm#Locks%20and%20Keys

Howzzat?