Most version upto and including 1.6.12 included the 3 versions of the config file.
1.6.13 was changed, so that people could not complain that there bot was nto functioning correctly, when infact it was, it just hadn't been configured properly.
I more than strongly sugest that you use the eggdrop.conf included, rather than reverting to a previous version of eggdrop.
There is infact no differance between each config file, and eggdrop has no way to distinguish them. The plain and simple truth, is the lack of sontnt in some fo them.
While simple, is enough to get the bot started, it also causes a lot of trouble, because it doesn't provide the setting most people need to change.
Yes it may take a long time to complete all settings, but the fact remains, you will not need to do it again, providing you take backups.
as ppslim said use the latest version as the others versions have errors for example eggdrop 1.6.13 has serious security problems so dont use this i know first hand