Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
Files xxxx.bat of which there are several. Change era global layer, uires, qclocations, splash, uimusic, etc.
Happy to check if you run out of options. Are you running separate ETO installs for different eras? Sounds like a good move, then you could really play around with the country.xml so that different countries default in the spawns, without the complexity of era-specific air spawns.