Definition: Bustle Joke

MIKE: My owld woman uses only one week’s edition ov the Sun and yesterday's stale coffee rolls compressed in her behind machine.

In the 1890's, women typically wore very large bustles that pushed out the back of the skirt below the waist. The bustle was padded with a small saddle cushion or a padded roll called a "bum roll" or (in a now-outdated Victorian expression) a "dress improver." The joke here is that Mike is admitting that instead of using a regular "dress improver," his wife stuffs her bustle with newspapers and coffee rolls.