The Pali Text Society published editions of the Pali Tipitaka, starting in about 1890.
I assume it was copied (transcribed) from one or more written sources, not from memory, is that so?
From what written documents/sources did the editor[s] of the PTS edition get the text? Were they manuscripts, or printed? And I'm guessing the PTS transcribed the text to Roman script?
Where (in which countries and/or by whom) were those source materials copied? Was it from one source or several?
Would you happen to know whether the source documents still exist today?
This answer says that different editions are more or less the same in every country ...
With the Pali editions, we inherit a complex manuscript tradition. In each country there are multiple different editions, both modern printed editions and older manuscripts. The ones we have ended up using are more or less random. The problem is that despite the many variations, the reality is that it is a huge amount of work to gather and collate them, and the end result is, “Yep, apart from these few instances, it’s pretty much the same as all the others.”
... still I'm wondering specifically where the text of the PTS edition came from (and where the work was done).