Matchdot II Anti-Glare Extension

I found glare from lights behind me was bothering me today at the range with my Matchdot II so I decided to install the tube extension that is provided with the scope.  I can not get it installed.  While it fits perfectly fine on the muzzle end of the scope (as does the shorter filter piece), neither will fit on the grip end of the scope.  I can see that the grip end is threaded but both pieces appear to be a slightly larger diameter than the grip end of the scope. I even loosened the mount at that end of the scope to ensure it wasn't causing an issue.

Any idea what I'm doing wrong?

The ends on the Matchdot are different sizes. Contact PhotoEscape, as I believe that he makes adapter rings to do what you are trying to do.

Kinda odd the extension tube don't fit the scope it was sent with! Usually the extension is installed on the Muzzle side of the scope.

Nope, only the muzzle side.

Several make rear shades. Photoescape, Dou Hall among others

Thanks folks.  Ordered one from DHECO.COM.  I assume the glare was coming from the lights behind me, thus I'm hoping a rear shade will help alleviate that.