\documentclass[10pt,a4paper]{article}
\font\oldunh=oldunh10 scaled 1000
\font\olfib=olfib8 scaled 1000
\font\olrfive=olr5 scaled 1000
\font\olrsix=olr6 scaled 1000
\font\olrseven=olr7 scaled 1000
\font\olreight=olr8 scaled 1000
\font\olrnine=olr9 scaled 1000
\font\olrten=olr10 scaled 1000
\font\olrtens=olr10s scaled 1000
\font\olrtwelve=olr12 scaled 1000
\font\olrseventeen=olr17 scaled 1000
\newcommand{\Ligature}{%
\input test_alphabet.tex
}
\begin{document}

Computer Modern Roman 10pt:\\{\Ligature}

Dunhil Roman 10pt:\\{\oldunh \Ligature}

Roman Fibonacci 8pt:\\{\olfib \Ligature}

Roman 5pt:\\{\olrfive \Ligature}

Roman 6pt:\\{\olrsix \Ligature}

Roman 7pt:\\{\olrseven \Ligature}

Roman 8pt:\\{\olreight \Ligature}

Roman 9pt:\\{\olrnine \Ligature}

Roman 10pt:\\{\olrten \Ligature}

Roman 10pt Sperrsatz:\\{\olrtens \Ligature}

Roman 12pt:\\{\olrtwelve \Ligature}

Roman 17pt:\\{\olrseventeen \Ligature}

\end{document}