I just came across these samples of 19th century Gotland dialect. I'm
not sure how to get from the "Lyssna igen på programmen" link to
somewhere where you can actually listen again to the programme (maybe
my browser's blocking it). But clicking on "Fäi-Jaken sidan" loads a
page from which you can hear modern readings of three letters written
by a Gotland farmer in 1889 in his native language. If you've looked
at the section on Old Gutish in Gordon's Introduction to Old Norse and
the final reading selection in there, you might recognise some of the
unique features that set the speech of Gotland apart from mainland
Swedish still in evidence in the 19th century, including archaic
details such as the survival of the Germanic diphthong /ai/, as well
as innovations such as /ju:/ > /jau/ (as in 'jaul' "yule").

http://www.sr.se/cgi-bin/gotland/program/index.asp?ProgramID=2474
http://www.sr.se/cgi-bin/gotland/program/artikel.asp?ProgramID=2474&Artikel=1787417