I doubt you'll end up with the same map because I used pre-genned terrain, but...
Seeds:
[SEED:593975651]
[HISTORY_SEED:1247353185]
[NAME_SEED:1567681258]
[CREATURE_SEED:1659002156]
[DIM:257:257]
And also, I changed these, but I'm not sure what impact they'll have on reproducing it.
[LEVELS_ABOVE_GROUND:20]
[LEVELS_ABOVE_LAYER_1:20]
[LEVELS_ABOVE_LAYER_2:10]
[LEVELS_ABOVE_LAYER_3:10]
[LEVELS_ABOVE_LAYER_4:10]
[LEVELS_ABOVE_LAYER_5:10]
[LEVELS_AT_BOTTOM:10]
Let me know how it works for you. This delicious region was on the far right side of the map, just under half way up, in a little valley tucked in the mountain range. If you don't have this, it probably didn't gen the same.
If you use the "Export Local Image" function on the Options(escape) menu, one of the files created will be the world gen parameters as used by DF to generate the world, including anything from PerfectWorld or the World Painter (I assume one of these is what you mean by "Pre-genned"), in which case the only cause of disrepancies in the world generated would be if you've modded your raws for things like the Entity_default.txt (strangely, changing which portions of the dictionary are available to your civ for names & such affects geography).
Wait, so you want the entire region gen file?
I have not modified the Entity_default.txt, but I do have custom rock layers, which probably has the same effect...
Custom Rocks probably does change it, but I haven't tried it, so can't say for certain (I know removing Aquifers has no effect though).
Using "Export Local Image" exports a picture of each the selected levels (I recommend only doing 1), the World History, the World Sites, & the World Gen Parameters used for the world in question.
Not the entire World gen file.
I know. It's too large to post here, so I need to find somewhere to upload it, though I have no idea.
What you will be getting:
There is the majority of the land mass in the west, with islands in the south east and a strip of land running up the eastern edge, there is also a smaller (partly connected to the rest) landmass in the north and a large mountainous region in the north east. The north west is supposed to be a "rift zone", where it's fairly flat with high volcanism, otherwise the majority of the volcanism follows the mountains.
There is a strip of ocean on the west, that is calm. The central ocean is terrifying. The majority of the savagery is in the south, but there are isolated pockets all over the map.