\documentclass[10pt,a4paper,twoside,onecolumn]{letter}

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\usepackage{graphicx}
\usepackage{lipsum}
\usepackage{tabularx}
\usepackage{lmodern}

\newcommand{\CO}{{\nicefrac{\raisebox{.2em}{\textsc{c}}}{\raisebox{-.3em}{\textsc{\kern -.1em o}}}}}

\begin{document}
\makelabels
\fontfamily{lmr}\selectfont

\begin{letter}
\address{%
    \ttfamily
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Hans Thomas {\scshape Reiser} \hfill ({\scshape cdcr} {\ttfamily\textnumero\ {\scshape g}31008}) \\
California Health Care Facility ({\scshape chcf}) &\\
\CO\ Dept. of Corrections \& Rehabilitation &\\
{\scshape usps PO} Box \textnumero 213040 &\\
Stockton, {\scshape ca} 95213+9040 &\\
United States of America &\\
}
}
\returnaddress{%
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{
\begin{tabular}{ll}
{\scriptsize {\itshape Be this letter undeliverable, return to}} &\\
Fredrick R. {\scshape Brennan} &\\
Modular Font Editor {\scshape k} ({\scshape mfek}) Fndn. &\\
\textnumero597\textsuperscript{\underline{A}} N. Raleigh Ave. &\\
Atlantic City, {\scshape nj} 08401+1081 &\\
United States of America &\\
\hline
    \begin{tabular}{ll}
        Telephone N{\textsuperscript{\underline{os}}}: & (818) 824-1764 ({\scshape sms} preferred)\\
                                                  & (609) 674-3889 (Google Voice, {\scshape sms} only)\\
    \end{tabular}&\\
\end{tabular}
}
}
}

\opening{Dear Mr. {\scshape Reiser},}


    Attached are some documents that I inadvertantly left out of my first reply to you. If you have replied since then, it is still in the mail and I haven't yet gotten it.

\closing{Sincerely,
\vspace{3em}
\signature{Fredrick R. {\scshape Brennan}}
}

\end{letter}
\end{document}

