I feel like giving up

Couple things.

One- bumpers are really hard to find, and realistically, there are probably hundreds of missing bumpers that are reduced to a tape in someone's attic. So with that area of search comes some frustration.

Two- Pokemon Live actually has some leads and we have made some kind of progress even if it's not huge leaps. So with continue effort I'm sure we can find more than we have now.

And at the end of the day I have to go back to A Day With SpongeBob as an example of something that wouldn't have been found without persistence.

As for a more relevant example, back in February I made a video about some lost 24 karat gold Game Boy
Advance SP systems, and it took months of the video just sitting there
for people to come forward with pictures and proof that they exist. And
just last week someone gave me some amazing in-hand pictures of it from
their own collection, which I never thought we'd see back when I made
the video.

So all things considered while you can't find what you're looking for as soon as you'd maybe like, definitely don't give up altogether.