I would add battery and charge/discharge circuitry to that list.
If you're looking to bring something that's worth fixing back to life, you might be best to find a relatively inexpensive solar light at a big box store and steal the needed components to be transplanted into your broken item. Of course, if the solar panel and/or switch are different dimensions, that's going to pose a problem.
It's a solar powered tractor lawn ornament that my mother gave me years ago. Looking around online, I'm not going to mess with it seeing how you can find them new.