The data available was really different, so it was more difficult to get as historically accurate geographic file. I had to create most of the files, using current data.
Trap5 for Greenland was published just after a substantial reform of the administrative organisation, so the historic data was relatively close to present-day. At least for the municipalities, so I only had to create/modify a few polygons. As for the cities (by) and settlements (bygd), it was a little bit more of a guessing game. One main barrier was that not only there has been changes of spelling, but also there are Danish names, Greenlandic names, but also old Greenlandic names! Some of the settlements have also completely disappeared, or had only been used during the summer by a couple of families, so finding any trace of it was very difficult.
The Faeroes only had geographic data for their municipalities, but nothing at the clerical level (præstegæld and sogne). The only map I had access to were the maps from Trap5, nothing digital. However, I noticed that their current postcode (the smallest unit geographic data I could find) could actually be grouped into the sogne level. I only had to change a couple of borders.