This article publishes the first stemma of the manuscripts of the fifteenth-century Icelandic romance Sigurgarðs saga frækna, taking in 58 of the 61 known witnesses. It capitalizes on digitally-native publication to publish all underlying data, presenting a fully open-data approach to stemmatics. The article shows how the post-medieval transmission of the saga supports previous claims about how Icelandic sagas in this genre circulated but also takes manuscripts containing Sigurgarðs saga frækna produced in the seventeenth to nineteenth centuries in the Dalir region of Iceland as a case study for a methodologically novel investigation of how scribes went about anthologization. Refining previous work on the manuscript filiations of Ambrósíus saga og Rósamundu, Sigurðar saga turnara, Hálfdanar saga Eysteinssonar, Nítíða saga, and Konráðs saga keisarasonar, and making the first outline of a stemma of Nikulás saga leikara, the study gives our first systematic insight into how the scribes of the eighteenth-century manuscript Rask 32 assembled their anthology, and how their work influenced subsequent anthologies that drew material from that manuscript.