Mine seemed to be glued on...but some pictures I've seen shows "plugs" of sorts. Does the model vary in the grill attactment?

Well, unless someone has done so in the past they should not be glued! They can feel very stiff. I carefully ease the panels off at each peg a little at a time... I have heard it mention to spray silicon oil in the pegs but never tried with the grills on.

Both ways of mounting can be found.
Work carefully when taking off the grills, they break easily, typically across the center.

Martin

-and I thought that it was only the M70's that had two ways of mounting

I have the "old" version with the glued grills. Damned job to remove them -and glue them back on again...