This paper focuses on the case of Zeelandic Flemish in Espírito Santo, an obsolescent language variety spoken by about twenty descendants of Dutch immigrants to Brazil in the nineteenth century. The speech of rusty speakers can be used to reconstruct the original immigrant language. We perform a historical reconstruc- tion of the old Zeelandic Flemish dialect as spoken in the days of emigration, with respect to three linguistic cases: (1) deletion of /l/ in codas and coda clusters, (2) subject doubling in inversion contexts and (3) the inflected polarity markers yes and no. Our findings demonstrate the historical value of transplanted dialects or speech island varieties (Rosenberg 2005). However, a comparison of our findings with historical data demonstrates that reliance on rusty speaker data alone may sometimes lead to incorrect conclusions and that the data should always be considered from the perspective of language contact as well.