I've been interested in this same thing ... curious to hear feedback/input. If I build a StarWars topper with the likeness of C3PO and R2D2, do I need a license or just go for it?

If its a one off for yourself, it is fine. Kinda like if I need drop target decals for IJ, I just used an nos one and had 3 made.

If you build a mod for personal use, it’s ok to use anything you want. In order to sell the mod with licensed material, you legally need permission from the license holder. Will a big corporation come after a mod-maker? Probably not, but they could legally shut down someone making unlicensed mods. Best to not sell anything that would require permission from a license

Because JJP is the licensor, and depending on the license agreement, JJP might be responsible for enforcing copyrights surrounding the product that uses the IP.

If JJP doesn't protect the IP, then JJP could potentially lose the license.

But again, that all depends on what's spelled out in the license agreement.

Most probably are. Until someone goes into serious mass production, repeatedly uses IP without permission (especially for profit), or makes the brand look bad in some way, it's usually not worth a lawyer's time to go after them.

Star Wars is a bit of a different animal when it comes to copyright. Traditionally, Lucasfilm has allowed people to play in the universe, so long as it's clear it's not an official work, and it's not for commercial promotion or profit. Not all copyright owners allow that. But, that's part of the reason why Star Wars specifically has thrived--allowing fans to explore their creativity and keeping the IP alive and relevant in the process.

But in general, making something with someone else's IP for personal use only is generally ok, but making it for others is generally not.

or design something that isn't copyrightable - something generic.
Volcanos obviously can't be copyrighted... but a specific shape/sculpture can.
A ship can't be copyrighted; but if it has a similar shape to a POTC ship with the same name... you're asking from trouble.

At least that's my take. Good luck if JJP tried to enforce a copyright on a pinball part that is generic.

Slowly but surely good ol’ Disney is gonna make sure that no longer happens lol. Money-hungry Disney isn’t afraid to go after even the smallest operations, so I’m quite surprised with the mod community thriving with licensed pins of Disney. I mean they don’t mind tackling a child’s grave or a day care.
Strange...

No, it's usually part of the agreement when you license something. You agree to defend against infringement as a licensee of the IP or item, etc. I've never seen a licensing contract without that clause. He's doing what he's contractually obligated to do. In fact, I was surprised that stuff you had that included actual different art from the movies didn't get a cease and desist since it wasn't just "inspired by" the movies.

As long as you're making mods using licensed stuff for yourself, you're good. It's when you start making mods with licensed or copyrighted IP/art them available for sale or whatever to others that you step over the line.

For trademarked items you have to enforce even a minor commercial infraction or you may loose the ability to enforce it at all .

I eat in a tiny vegetarian restaurant that sold Arnold palmers . They were contacted to stop using the name on the drink. The place has 6 seats.

Thats pretty accurate.
In another thread somebody was talking about Robin Hood as a licensed them.
Robin Hood is public domain and does not require any kind of license.
However, if you were going to make a Robin Hood theme that depicted the Disney cartoon Rendering of Robin Hood that would require licensing though Disney.

In another life I used to make replica movie props. I know people who received C&D letters after a few dozen and some after a few hundred items produced. What I found was earning that C&D letter was more about who's bad side you were on or who's "side business" you were threatening vs actively being sought out by license holders. It just takes one person to send an anonymous email.

A friend of mine makes product for Chryslers, Chrysler sent him a C&D for including decals that they had copyright on like "SRT" "Air Grabber" Super Bee"

Mind you they were not whining about the product, but the decals that were included. This took all of a hot 2-3 weeks after he started his business.. So if you think you are too small to be noticed, there is companies that have people who do nothing but look for infringing items.