Setting fonts in texinfo

I'm using the GNU texinfo package to generate both PDF and .info files 
from a .texi file.

I'm trying to update an old .texi file (not changed since 2001) and 
generate the same PDF output. I've resolved a number of issues, but 
there are a couple outstanding. In the old PDF, the title was in 
Helvetica and body text is Liberation Serif. In the new PDF, both are 
Computer Modern.

I've read everything that I can find about fonts, but I'm not able to 
change the fonts. Nothing that I do seems to work. Everything I have 
tried generates errors.

In my .texi file, before any \setfont directives, I have 
\def\fontprefix{uh} which, if I read the pdftex.map file correctly, 
should select the NimbusSanL font set (e.g. uhvr8a.pfb). I get the 
following errors:

mktexnam: Could not map source abbreviation for uhss10.
kpathsea: Running mktexmf uhss10
! I can't find file uhss10'.
<*> ...ljfour; mag:=1; ; nonstopmode; input uhss10`

Does anyone have a example .texi file which sets the font family to use?

-- 
Michael Eager