html2latex rendering quotes as <93><94> and \223 \224 in vim/emacs... what's goning on?

OS = Linux

I have documents that I am converting from HTML to LaTeX. The produced LaTeX file has some strange characters for the double quotes and quotes.

When viewed in vim the double quotes show up as:
<93> for the open quotes
<94> for the close quotes

when viewed in emacs the double quotes show up as:
\223  for the open quotes
\224  for the close quotes

My problem is that I am importing them into LyX (a LaTeX document processor) and LyX is converting both to closed quotes.  I was going to sed the document and change the strings and post process them later, but they are not recognized by sed.

What kind of characters are these?

$ grep -e '\223' file.tex
grep: Invalid back reference

$ sed -e 's/\223/TAG233TAG/g' file.tex
sed: -e expression #1, char 18: Invalid back reference

for <93> and <94>:

sed produces no output:
$sed -e 's/<93>/TAG233TAG/g' file.tex |grep TAG

cat just shows a "?" in a diamond when it encounters single or double quotes.  

$ cat file.tex
text text text {\it ¿quoted text.¿} I don¿t know what is going on.

I am hoping to find a way to convert these, but don't know what kind of characters these are.  

Thanks,
Frank