Well, I found the character I want in the two fonts I'm using. I'm sure
I don't understand all of the details, however.

\char129 gives the character I want, a true straight single quote. My
research seems to indicate that the position should be influenced by the
encoding of the current font, but this doesn't appear to be the case.

A cursory examination of 

\usetypescript [sans] [vera] [ec]
\usetypescript [sans] [vera] [texnansi]
\usetypescript [sans] [vera] [8r]

all appear to produce the same result.

-- 
Stuart Jansen <sjansen@gurulabs.com>
Guru Labs, L.C.