Ok, so, after finding information at
this git repo detailing what seems to be the current API, and
this mapping of old IDs to the new format, it looks like I replace
Code:
GetMapNameByID(261)
With something like:
Code:
local SilMapDetails = C_Map.GetMapInfo(81)
local SilMapName = SilMapDetails.name
.. or some more condensed lua-ism (not very familiar with the language yet)