Here is the first save of the museum IV world, right after it was generated, before anyone played.
It was generated in a freshly installed version of DF 51.13,

There were no installed mods, but two lines of code were changed from vanilla before generation, both in
entity_default.text , for the EVIL entity (goblins)
[MAX_STARTING_CIV_NUMBER:100] was changed to [MAX_STARTING_CIV_NUMBER:4]
[WORLD_CONSTRUCTION:ROAD] was added.

The maximum number of goblin civs was changed as otherwise any world generated would be completely overrun by goblins. Note that additional goblin civs are often generated during worldgen whenever dwarves dig to deep.
The ability for them to build roads was added to make the map a bit more interesting.
Both of these should only affect worldgen, and the world has been running on true vanilla files since.

The relevant entry from the worldgen.txt file is packaged with the save file. (The maps were drawn with perfectworldDF)
It's hard to check, but I think these were the worldgen seeds, it's at least the last world I generated with this worldgen file according to gamelog.txt:

Generating world using parameter set MUSEUM IV
Seed: 3KI5CjEHdwDQDAjKuj1k
History Seed: 9osJj5fh0XZheUNPdoOn
Name Seed: onWxU3uX1uvrfr2ifi49
Creature Seed: WOGTVMFNZC6uxXAgqm2z