I am preparing a book using the Octavo class and would like to use one of Peter Wilson's titlepages, but am having some trouble locating the publisher's logo at the bottom of the page. Using \titleS (as defined below) puts the logo not quite at the bottom. I tried adding vertical space, but could not move the logo down. I use MikTeX on Windows. Would anyone be able to help?
\documentclass[10pt,foolscap]{octavo}
\usepackage{titlesec, type1cm}
\usepackage[cam, noinfo, a4, center]{crop}
\setlength{\textwidth}{7.2cm}
\setlength{\textheight}{12cm}
\newcommand*{\plogo}{\fbox{$\mathcal{IW}$}}
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\renewcommand{\headrulewidth}{0pt}
\renewcommand{\footrulewidth}{0pt}
\fancyfoot[CE,CO]{\thepage}
\fancyhead[CO]{\scshape\nouppercase{\leftmark}}
\fancyhead[CE]{\scshape{Practical Agitation}}
\renewcommand{\chaptermark}[1]{\markboth{#1}{}}
\renewcommand*\footnoterule{}
\newlength{\drop}
\newcommand*{\titleS}{\begingroup
\drop = 0.1\textheight
\centering
\vspace*{\drop}
{\Huge Practical Agitation}\\[\baselineskip]
{\large\itshape John Jay Chapman}\\[\baselineskip]
\vfill
\rule{0.4\textwidth}{0.4pt}\\[\baselineskip]
\begin{center}\plogo\end{center}\par
\vspace*{\drop}
\endgroup}
\begin{document}
\pagestyle{empty}
\titleS
\clearpage
\end{document}