Looking for German late-period documents, I stumbled across this database/project:
'Europe´s archives document its political, economic, and cultural development from back to the Middle Ages.'
It's an archive of documents from dozens of collections, in various stages of being scanned, abstracted, and transcribed. The dates vary from early Europe to into the 19th century.
What's distinctive is that when a document is complete, it provides scans of the whole document (both sides!) plus a description, plus a transcription of the text.
The collections are concentrated in Europe: German, Austrian, Czech, Polish, Italian, Romanian, Slovenian, Hungarian... and still growing.
This is a super view onto original working documents of our period, with original wordings.
The catch is - you have to speak something other than English to make the most of it! Latin helps, but the majority of the texts are in German.
For those who love calligraphy, charter-style documents, and original texts, though, it's a boon.