This mod reimpliments the old parts. For all your Nostalgic needs! The mod used to use multiple configs, but now it simply combines all the parts into one folder and restores the old versions of every removed or modified part. Currently parts from 0.13.3 are restored, and everything nerfed/changed in 1.3, 1.4, 1.5, and 1.6 has a classic version too! Version 0.7.3 and below of the mod have two configs, one reimpliments the old parts from 0.13.3, with some minor balance changes, and the other reimpliments the 1.3.1 parts which were replaced, modified, nerfed or removed in 1.4. To install, just choose which config you want, and extract that config's .zip file into your GameData directory.
EDIT: Should now be compatible with AVC!
Download on Spacedock.
EDIT EDIT: Proof for reddit