98%; just don't know what's missing in world 4-7

Hi!

I just wondered if anybody knows if there are any secrets in World 4-7 that I dont know about. I completed that level a hundred times still don't know what I missed out. Is there any cannon that's hard to find or what?(I collected all letters,all barrels and all bananas(even if you dont need that for 100%))

I hope somebody could help me because I've got this game for 8 years and now I finally wnated to get 100%

I'm stuck on the same problem in level 4-7 (Donkey Kong Land). Have you figured out yet what you're missing?

Also, maybe you might be able to help me - do you know where the N is in 1-9 or how to get the letter K in 3-4?? In 3-4, I believe the K is on a platform/cliff above the start of the level, but I can't figure out how to get up there.

Any help regarding these levels greatly appreciated.