The smallest P60 lights are the CR123 type.
1. Surefire 3P= 3.9in
2. Surefire 3P Parts = 3.25in = This is the Smallest I have and with a Dereelight R2 it is the lightest, but I rather have an M30 eventhough its heavier.
3. Solarforce L2m = 3.90in
There are more, but these are the ones I remember.
Now with the Malkoff E-Series bezel then
1. E1E plus Malkoff E-Series bezel = you could fit any Malkoff P60 drop-in. Others from Dereelight and DX will not fit.
2. Aleph CR2 body plus E twistie and Malkoff E-series bezel
Good luck,
Jose