How to make certain buildings available to factions they dont "belong" to?

Heya all.

After "mastering" the art of adding new units, applying skins (already existing) etc. to them I've run into a new problem when "modding". Namely, I'd very much like to enable the Sweboz of creating those awesome Celtic large walls (Equialent of Stone Walls). Now, how exactly would I do this? Anyone can give me a pointer in the right direction?

Well, I know its a lot easier than adding units...

I don't have the files with me now, but I think the file is eb\data\export_desc_building.txt, (back it up first of course)
after each building there should be a list of factions that can build it
find stone_walls and add "germans" to the line, while you're in there, find the large bath house building and add germans to it too. I don't know what the walls will look like though but the last time I checked the Sweboz had their own faction specific description for bathhouses.

cheers!