\documentclass[landscape]{article}
\usepackage[T1]{fontenc}
\usepackage[left=0.5in,top=1in,centering]{geometry}
\newlength{\bkletheight}
\newlength{\bkletwidth}
\newlength{\traywidth}
\newlength{\trayheight}
\setlength{\bkletheight}{118mm}
\setlength{\bkletwidth}{120mm}
\setlength{\traywidth}{150mm}
\setlength{\trayheight}{120mm}
\begin{document}

\begin{center}
\framebox[2\bkletwidth][t]{%
	\raisebox{-1cm}[0pt][\bkletheight]{%
	\begin{minipage}[t]{\bkletwidth}
	\input{ceremonials_i.txt}
	\end{minipage}
	\begin{minipage}[t]{\bkletwidth}
	\input{ceremonials_o.txt}
	\end{minipage}
	}
}
\end{center}

\end{document}