300+ LED white xmas lights fixable? (Kitchener)

A project. Not currently working. Spare bulbs included.
4 bulbs are the original included spares in package.

Strings of white, and warm white LED lights. Estimating 300 bulbs.

1 string, 30+ blue. Faded.

See 3rd photo for condition.
Some were previously capped.
Some sockets are currently empty
Apparently someone attempted cutting and splicing strings together at some point. One of these worked, up to the splice, until I took it apart to try to get the full length working...
...and I'm never going to get to this project.

If you can't get (all of them) them to work:
The most environmentally responsible disposal method I can find currently available in the region, is to cut the bulbs off with wire cutters, and the wires (with casing) can be donated or sold as ewaste cables - which pay a better per lb price than devices.

I'd rather someone has an opportunity to fix and use them, or learn something, rather than just junking them.