If the starter motor on your car stops working, you have two options: Replace it, or repair it. Most people (including me), would probably just buy a new starter and chuck the old one in the trash if there was no easy way to get it working again. Some people though, like the host of this video from the YouTube channel, will take to time to rebuild it properly.
As a part of the channel's E30-chassis BMW 325i restoration, it put together an incredibly comprehensive video documenting a refresh of the car's electric starter motor inside and out, and it's surprisingly interesting to watch. The host takes apart every piece of the motor, taking the time to preserve original parts when possible, saving all the pieces that haven't been worn out by years of use. He even polishes metal and paints parts that no one will ever see when they're driving the car. That's a true dedication to perfection. By the end of the video, he has a starter that looks like it's never been used.
If you have 20 minutes to kill, this video is definitely worth the watch. Check it out here.