This article explores representations of south-western speech in nineteenth-century dialect writing. It draws on a selection of specimens from the Salamanca Corpus in order to determine what they can tell us about the language of south-western speakers at this time. By focusing on periphrastic do and pronoun exchange, I argue that representations of south-western dialects can be taken as a missing link in the history of these two grammatical features. In fact, the analysis of their distribution and frequency, which this article explores in dialect writing for the first time, shows that they accord with later evidence to an interesting degree. At the same time, the data are placed within the third-wave sociolinguistic models of enregisterment and indexicality so as to show that the conscious representation of these morphosyntactic features reflects contemporary perceptions about their use in south-western dialects while they reveal indexical associations between place, speaker and speech. This article thus seeks to contribute to the history of south-western dialects, while underscoring the validity of dialect writing as a source of Late Modern English speech where the structural and ideological dimensions of dialect intersect.