After doing this with Boomer a few days ago and after a recent suggestion based on doing this on the server I decided to put this somewhere so people can refer to it. You can build your own dupes for trainings/tryouts or anything and get them on the server. It's pretty easy to do and only takes a few minutes, if that. This will work on any server with the Advanced Dupe so Imperial as well (probably, I ain't ever been on there).
Do remember there are hundreds of dupes already on the server, don't waste time re-creating a dupe that already exists.

1. You're gonna need 2 addons.
- Smart Weld. This will make your life 1000% easier when welding the dupe together.
- Advanced Duplicator. This will let you save your creation.

2. Now you've got the tools you'll need you can head into a singleplayer game. Any map, doesn't matter. Once you're in you can build away. Try not to use too many props, this is going to be used on the server at the end of the day and performance is a factor at the moment. You can check the main CW discord #spawnlist channel to get a list of props on the server. Here's what I built:S3Uzqhk.jpeg

3. Once you're done building your super-duper, massive, ultra-cool training whip out your smart weld tool. Make sure your "Force Limit" is at 0 and "Remove old Welds" is ticked. The rest of the settings are up to you. Once those are set, hold E and Left Click until all of your creation is highlighted. Here's mine:tkLHdfy.jpg

4. Once your creation is all highlighted hold E and Right Click one central prop. Can be the one at the front or middle or a block in a corner. It is very important that you hold E and Right Click and do not just Right Click. That will weld all the props to the one you clicked.

5. You're creation is ready to be duplicated. Whip out your advanced duplicator, right click the prop you welded everything to. Then hold Q and click on "Save" give it a relevant name and add important notes to the description, location for the dupe to be used, etc.

6. Now your dupe is saved you're almost done. All that's left is to give the dupe to a Staff Member. Open up a file explorer and head to "SteamLibrary\steamapps\common\GarrysMod\garrysmod\data\adv_duplicator". Find the .txt file with the name you just saved. Give this file to a Staff Member. You can upload to pastebin or just drag into discord or literally any other way.

Congrats! You're done!
These next parts are for the Staff. You don't need to worry about doing any more.

Spoiler: Staff BitShow