There were many mods or parts that were modeled in years, models or mods that were left alone and never got updated after their original publishing, thankfully, their licensing were open and let others take their job and continue their awesome works but, no one ever took it upon themselves to do it. Here are few of those mods :

Concave Construction Kit

Wayland Station Rings

ZZZ Models (some of the parts are being used in other packs but not those that are included in this mod)

Now, Concave construction kit give you some parts that look concave, they are awesome if you want to add parts to your vessel in ways that are not normal but very useful.

Stational Rings, give you three different rings to be used on your space stations. Two of them are solid but one is profile rig and it gives over 80 attach nodes in every direction (top, bottom, out, in,...)

Finally, from ZZZ's awesome work i took three radially mountable models, and,... made two variants of each, one being a radially attachable tank, the other? RAPIER engines !!!!

For installation, simply put the content of the pack into your game data folder. If you don't add B9Animation, the animation of the fins on rapier engines won't work but the engine will be ok, without B9PartSwitch, you may hate the profile ring but with that plugin, you will sure have fun time putting your ring together as a puzzle ;)

Finally all the parts have tweak scale module added to them so have fun with it :D

Unfortunately the licensing of Wayland and B9 had conflicts, so I had to remove B9 plugins from distribution pack, You need to download the plugins manually, here are the links :

B9AnimationModules

B9PartSwitch

Models and parts would work without these two mods from B9, But I highly suggest them, B9 animation module is responsive of animating the fins on the rapier engines and part switch is used to toggle nodes on/off in edit mode for making your life easy

here is the forum link