If you want to use non standard fonts, I think, you should use XeLaTex to compile your file. After installing the font in the system, this just worked on my Ubuntu:

\usepackage{mathspec} \setallmainfonts(Digits,Latin){Old Timey Mono}

\begin{document}

Just test some equation \begin{equation} \frac{e^x}{2-x} = \int_0^\infty f(x)dx \end{equation}

\end{document}