Here is the box I made for my Fatman.  It measures 12" x 7" x 3".  Parts
are a bit crude but I was excited to get the thing running and it has
worked so far.  The front panel is laid out like the block diagram from
Paia.  The ins and outs printed on the top (front panel) coincide with
the jacks on the back.  Keeping in mind that nothing is really on the
panel except for the pots, there is plenty of space to add jacks and
such when I get to the mods I want to do.  I'm hoping to add these
things in their logical place (i.e. ext. input above osc. 1 with a pot
and line going to the mixer, ext. vco cv (or lfo) below pitch pot,
etc.)   I don't use a rack extensively so the table top box is handy for
me although a similar panel could be made for rack mount.  One thing I
always liked about the old Paia modules (and the old Korg patchables)
was the graphic approach to the panels.  I've tried to lay the FM out in
a similar logically graphic manner.  Any comments...  email me or post
them the the list.