WonderSwan Console Sherbet Melon Junk

This is part of my brother's unwanted items that I'm clearing out.

The box is wet? It's tattered.
The plastic case is also crushed. The instruction manual also feels like it got slightly wet at some point.
On the main unit, the film on the LCD screen is peeling up. There are also what look like stains on the left and right sides of the screen.
When I asked my brother about it, he said, Oh, that's a common thing. The battery springs are rusted, possibly due to leakage.
I tested it with batteries I had on hand, and the power-on sound and logo appear, but I cannot confirm its operation as I don't have a game cartridge.
There is not much sign of use.

I will put it in the mailbox as is. Thank you for your understanding.

WonderSwan
Sherbet Melon