Sewing for small dolls (marionettes actually)

Puppetry is a serious hobby for me, and I've started making some
marionettes (the kind of puppets hanging from strings).  These are a
little smaller than most, being only about 18" tall.  The series I've
started on is "Great Scientist's from History", and needless to say
involves clothing the marionettes in suits.

  I have minimal sewing skills, but managed to make the suit for
George Washington Carver (well, mostly finished it).  I've realized
that those tiny arm holes as I join the sleve to the suit are pretty
difficult.

  I've tried a few rounds of hand-sewing on that area, but have never
had satisfactory results.  My best results were actually using the
sewing machine, but that was certainly a challenge as well, since the
arm hole was only about 1/2" diameter.

  I'm sure I will improve with practice, but I wonder if there is any
equipment that would make it easier.  I've already purchased a small
"shirt tailer" foot, which really helped on the small hems.  I'm
actually using a very old singer, but have been told that the better
quality modern machines have much finer control of speed, which should
help as I make small items.

  I wonder if there are any specialized sewing machines which make
this kind of small work easier?

  Other advice?

Joe Dunfee
my real E-mail (in mangled form) is
TO MAIL ME joespuppets GET RID OF @paonli CAPITAL LETTERS ne.com