Those 1SMD LEDs will be plenty bright. On Cyclone especially due to its great light show, I tried to use LEDs as sparingly as possible. Colored incandescents look great when used in the Mystery Wheel in the backbox. Just enough color but you still retain that slow decay from the lamps. I believe you could use a LED-OCD board to retain the effects if you wanted to go full LED.
You might be able to use a little heat to smooth that decal out, possibly re-affix with some 3M spray adhesive.