Scott,
I got the reamer from McMaster.  They are available in increments of
0.0005 ".  Being that small of a diameter, it is very short.  I ground
down the end so I could press/pinch on a long piece of SS tubing (I
didn't buy the one I had - I would check McMaster for tubing).  Reaming
is done slowly and by hand.  Most of what the reamer takes off is a lip
or burr formed at the ends of each hinge segment.  Tolerances of the MS
hinge will vary, but most fall on the large side.  Unfortunately this
diminishes the benefit.  I would love to find one on small side to ream
even more of the hinge surface, ideally all of it.  The welding wire is
held to a very close tolerance .  I don't know why but I'm glad it is.
(-can be purchased in 1 and 5 lb packs of about 36" long pieces at your
local welding supply store) In your hands, the hinge will feel stiffer
than the original.  Most new hinge material tends to have some curl to
it.  It frees up nicely once screwed down to a flat surface.  Note that
if your hinge surfaces are not flat, you will add friction to the
system.  
I have not experimented with other tolerance combinations/reamer sizes.
 If one could find a source for slightly larger wire, just above the
maximum range of MS hinge (0.098"),  a uniform ID over the full length
could be guaranteed.
Even with luck-of-the-draw MS hinge material the results have been
excellent.  If you go tug on my aileron, for example, you will not see
any relative movement between the hinge halves  -in the air, no more
bouncing ailerons.  That bouncing was the primary source of wear on the
original MS hinge.  As measurement showed, all the wear was vertical.
I lube them with LPS2 once a year.

Marv's potential source for a super long reamer is worth investigating.
 My longest hinge is in the elevator trim tab (MKII).  I had to attack
it from both ends.
Good luck!
Chris