Here is some information I've come across about the Mummy II.
The first versions of the Mummy II had a two piece stem like so..
This version of the stem fits on MX boards remarkably well.
However it does sit higher than the MX versions of the cap, like so (the green on the left is MX, two on right are Topre)
The two piece Topre stems do have about the same profile as a Bro Bot V2, so if you have a row of Bro's plus some 2pc Topre Mummy IIs, they will have the same profile.
From PunksDead -- I changed the Topre stems to 1 piece during the PWB mummy sale, so anything prior to that has the 2 pronged Topre stems.
PWB sale ---
https://geekhack.org/index.php?topic=61989.0