Patrick;

I don't know what you mean by "key barrel"...first, we need to understand and use common terminology...shown following, are a Nieman [u]lock cylinder[/u]and keys:

...whose flat [u]tail piece[/u] fits into, and turns the [u]Ignition switch[/u].

You need to remove the lock cylinder and determine if it is the lock cylinder itself OR the switch which is hard to turn. Insert key and turn to IGN ON position, push release button behind panel to remove. For additional notes on this, see: http://www.intelab.com/swem/service%20notes.htm#Body .

If the electrical contact itself is intermittant, it would be a great time to install a Start Pushbutton Upgrade which bypasses this contact alltogether, AND prevents future key breakage...and you wont even need to cut open the ignition switch (sorry if you had you heart set on this!...of course you could still dissect it, if you feel this is something you absolutely have to get out of your system....).

My experience with locks and keys is broad, but maybe not absolutely complete...as far as I know, the [u]keyways[/u], for door and ignitions were [i]never[/i] the same (I have seen a replacement lock cylinder recently available with what looks like possibly a new keyway, I have no first-hand experience with these). Also, the length of both the ASSA and Nieman keys used for ignition are longer (6 pins or tumblers) than the door keys (5 pins)...so something was undoubtably changed if one key fits into both locks.

Cheers