You know those Communicator Parts that you dig up from the sand and give Gulliver to help him out? Instead of giving them to Gulliver, keep all five of them in your pockets until the next in-game day and you'll find them transformed into Rusted Parts later!

What happens if you keep the communicator parts?

When you find his Communicator, just leave it in your inventory and don't return it to him. Then when the next day begins, the Communicator will transform into a stack of 5 Rusted Parts in your inventory! This happens because Pirate Gulliver is no longer on your island, so it can't be returned to him.

Can I keep Communicator parts?

The most efficient method!

Alternatively, you can choose to keep the communicator parts in your pockets and wait for the next day. The Communicator Parts will turn into Rusted Parts. This is the most efficient because you can get up to five at a time (Sorry Gulliver!).