How many versions of Magnepan SMG exist?

My son bought a used pair of SMGs that are much wider than company specs indicate. Much of the width is in solid wooden "wings" on either side of the active surface.

To improve his WAF, he would like to remove most of the extra width (so they are less noticeable when in use, and can be easily "hidden" when not), but he's concerned about possible degradation
of performance.

Any info regarding this, or results from similar experimentation, please??
Jim