Legacy question but almost SVX

[svxxx26]

Thought I'd post this to see if any technically experieced members had any info on this.
I had a WRX steering wheel I wanted to put in my '93 Legacy - figured it ought to go right on there....WRONG. The Legacy threads are smaller. Anyway, when re-installing the old wheel, the dang thing rubs against the steering column plastic housing! My mechanic was at a loss, something was altered in the process of removing the old wheel but what? He's gonna tear into the column next week.
I'm wondering though, could I get an Impreza part to replace the Legacy part ("part" being the thing the steering wheel actually bolts up to) and put the WRX wheel in like I'm craving???
ANd just what could have possibly gone so bad in the process of removing the Legacy wheel???

The SVX angle is this: The Legacy wheel and the SVX wheel are visually identical on the outside. So can I assume that the Lecacy and SVX wheels interchange? and that I can't put the WRX wheel in the SVX either??

Man I love that WRX wheel...