Frequent Warning messages using gv

[Fergus Daly <fergusd84@outlook.com>]

Whenever I use gv on a PostScript file as in
$ gv filename.ps
then a (usually) successful display is (almost invariably) accompanied by Warning messages about font conversions.
It is not obvious what limitations or errors are affecting the displayed output, if any, and I have got into the habit
of issuing the command with the qualifier
$ gv filename.ps 2> /dev/null
However: the Warning messages whilst occasionally very esoteric nearly always include the form
Warning: Missing charsets in String to FontSet conversion
Warning: Cannot convert string "-*-Helvetica-Bold-R-Normal--*-120-*-*-P-*-ISO8859-1" to type FontStruct
Warning: Cannot convert string "-*-Helvetica-Medium-R-Normal--*-100-*-*-P-*-ISO8859-1" to type FontStruct
Warning: Cannot convert string "-*-Helvetica-Medium-R-Normal--*-120-*-*-P-*-ISO8859-1" to type FontStruct
Warning: Cannot convert string "-*-Helvetica-Medium-R-Normal--*-140-*-*-P-*-ISO8859-1" to type FontStruct
Is there some additional fonts package or group of packages that I could usefully incorporate into my Cygwin setup that
would reduce warnings when using gv? (And maybe improve the rendering of outputs.)
My directory /usr/share/fonts/microsoft/ contains 120+ ttf links, though none looking anything like helv*.
Thank you.