I just realized my instructions were incomplete, sorry I was rushing out the door the first time.
The Gravity Wells are .sbmodule files. They too go into the GalCiv \Data directory. But there might be an additional step involved.
SB Module IDs have to be contiguous. If you leave a gap, all modules after the gap will show up on the screen where you decide what module you want to build next, but they won't allow themselves to be 'planted'.
Stock GalCiv IDs go up to 55. The two Gravity Wells modules are IDs 57 and 58. Andre_0's other SB Module in the Library, Xeno Mind Control Station is ID 56. If you download and install all 3, there will be no issues. If you just install the two Gravity Wells, you need to open the files in Notepad and renumber them from 57 and 58 to 56 and 57 (the IDs are also used to sort the modules so it's best to keep their positions the same).
Sorry for the confusion, it would be ideal if Stardock removed the 'must be contiguous' requirement for SB Modules as it makes sharing user-made SB modules a little sticky.
~SDC~
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